diff --git a/src/lib/es2015.core.d.ts b/src/lib/es2015.core.d.ts
index ccada2e0069c9..4d48d5cf40aaf 100644
--- a/src/lib/es2015.core.d.ts
+++ b/src/lib/es2015.core.d.ts
@@ -9,7 +9,7 @@ interface Array<T> {
      * predicate. If it is not provided, undefined is used instead.
      */
     find<S extends T>(predicate: (this: void, value: T, index: number, obj: T[]) => value is S, thisArg?: any): S | undefined;
-    find(predicate: (value: T, index: number, obj: T[]) => boolean, thisArg?: any): T | undefined;
+    find(predicate: (value: T, index: number, obj: T[]) => unknown, thisArg?: any): T | undefined;
 
     /**
      * Returns the index of the first element in the array where predicate is true, and -1
@@ -20,7 +20,7 @@ interface Array<T> {
      * @param thisArg If provided, it will be used as the this value for each invocation of
      * predicate. If it is not provided, undefined is used instead.
      */
-    findIndex(predicate: (value: T, index: number, obj: T[]) => boolean, thisArg?: any): number;
+    findIndex(predicate: (value: T, index: number, obj: T[]) => unknown, thisArg?: any): number;
 
     /**
      * Returns the this object after filling the section identified by start and end with value
@@ -330,7 +330,7 @@ interface ReadonlyArray<T> {
      * predicate. If it is not provided, undefined is used instead.
      */
     find<S extends T>(predicate: (this: void, value: T, index: number, obj: ReadonlyArray<T>) => value is S, thisArg?: any): S | undefined;
-    find(predicate: (value: T, index: number, obj: ReadonlyArray<T>) => boolean, thisArg?: any): T | undefined;
+    find(predicate: (value: T, index: number, obj: ReadonlyArray<T>) => unknown, thisArg?: any): T | undefined;
 
     /**
      * Returns the index of the first element in the array where predicate is true, and -1
@@ -341,7 +341,7 @@ interface ReadonlyArray<T> {
      * @param thisArg If provided, it will be used as the this value for each invocation of
      * predicate. If it is not provided, undefined is used instead.
      */
-    findIndex(predicate: (value: T, index: number, obj: ReadonlyArray<T>) => boolean, thisArg?: any): number;
+    findIndex(predicate: (value: T, index: number, obj: ReadonlyArray<T>) => unknown, thisArg?: any): number;
 }
 
 interface RegExp {
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index ee5600601aba2..827c2aaddd50c 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1273,13 +1273,13 @@ interface Array<T> {
       * @param callbackfn A function that accepts up to three arguments. The every method calls the callbackfn function for each element in array1 until the callbackfn returns false, or until the end of the array.
       * @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
       */
-    every(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean;
+    every(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean;
     /**
       * Determines whether the specified callback function returns true for any element of an array.
       * @param callbackfn A function that accepts up to three arguments. The some method calls the callbackfn function for each element in array1 until the callbackfn returns true, or until the end of the array.
       * @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
       */
-    some(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean;
+    some(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean;
     /**
       * Performs the specified action for each element in an array.
       * @param callbackfn  A function that accepts up to three arguments. forEach calls the callbackfn function one time for each element in the array.
@@ -1303,7 +1303,7 @@ interface Array<T> {
       * @param callbackfn A function that accepts up to three arguments. The filter method calls the callbackfn function one time for each element in the array.
       * @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
       */
-    filter(callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[];
+    filter(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[];
     /**
       * Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
       * @param callbackfn A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
diff --git a/tests/baselines/reference/2dArrays.types b/tests/baselines/reference/2dArrays.types
index f9f0e726dde3f..77fab3209e193 100644
--- a/tests/baselines/reference/2dArrays.types
+++ b/tests/baselines/reference/2dArrays.types
@@ -24,11 +24,11 @@ class Board {
 
         return this.ships.every(function (val) { return val.isSunk; });
 >this.ships.every(function (val) { return val.isSunk; }) : boolean
->this.ships.every : (callbackfn: (value: Ship, index: number, array: Ship[]) => boolean, thisArg?: any) => boolean
+>this.ships.every : (callbackfn: (value: Ship, index: number, array: Ship[]) => unknown, thisArg?: any) => boolean
 >this.ships : Ship[]
 >this : this
 >ships : Ship[]
->every : (callbackfn: (value: Ship, index: number, array: Ship[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: Ship, index: number, array: Ship[]) => unknown, thisArg?: any) => boolean
 >function (val) { return val.isSunk; } : (val: Ship) => boolean
 >val : Ship
 >val.isSunk : boolean
diff --git a/tests/baselines/reference/arrayFilter.types b/tests/baselines/reference/arrayFilter.types
index 7d91ef4ed322b..97c94995e5d5f 100644
--- a/tests/baselines/reference/arrayFilter.types
+++ b/tests/baselines/reference/arrayFilter.types
@@ -22,9 +22,9 @@ var foo = [
 
 foo.filter(x => x.name); //should accepted all possible types not only boolean! 
 >foo.filter(x => x.name) : { name: string; }[]
->foo.filter : { <S extends { name: string; }>(callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => any, thisArg?: any): { name: string; }[]; }
+>foo.filter : { <S extends { name: string; }>(callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => unknown, thisArg?: any): { name: string; }[]; }
 >foo : { name: string; }[]
->filter : { <S extends { name: string; }>(callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => any, thisArg?: any): { name: string; }[]; }
+>filter : { <S extends { name: string; }>(callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: { name: string; }, index: number, array: { name: string; }[]) => unknown, thisArg?: any): { name: string; }[]; }
 >x => x.name : (x: { name: string; }) => string
 >x : { name: string; }
 >x.name : string
diff --git a/tests/baselines/reference/arrayFind.types b/tests/baselines/reference/arrayFind.types
index 530f07be3f829..12eead1630cb8 100644
--- a/tests/baselines/reference/arrayFind.types
+++ b/tests/baselines/reference/arrayFind.types
@@ -24,9 +24,9 @@ const arrayOfStringsNumbersAndBooleans = ["string", false, 0, "strung", 1, true]
 const foundNumber: number | undefined = arrayOfStringsNumbersAndBooleans.find(isNumber);
 >foundNumber : number
 >arrayOfStringsNumbersAndBooleans.find(isNumber) : number
->arrayOfStringsNumbersAndBooleans.find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => boolean, thisArg?: any): string | number | boolean; }
+>arrayOfStringsNumbersAndBooleans.find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => unknown, thisArg?: any): string | number | boolean; }
 >arrayOfStringsNumbersAndBooleans : (string | number | boolean)[]
->find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => boolean, thisArg?: any): string | number | boolean; }
+>find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: (string | number | boolean)[]) => unknown, thisArg?: any): string | number | boolean; }
 >isNumber : (x: any) => x is number
 
 const readonlyArrayOfStringsNumbersAndBooleans = arrayOfStringsNumbersAndBooleans as ReadonlyArray<string | number | boolean>;
@@ -37,8 +37,8 @@ const readonlyArrayOfStringsNumbersAndBooleans = arrayOfStringsNumbersAndBoolean
 const readonlyFoundNumber: number | undefined = readonlyArrayOfStringsNumbersAndBooleans.find(isNumber);
 >readonlyFoundNumber : number
 >readonlyArrayOfStringsNumbersAndBooleans.find(isNumber) : number
->readonlyArrayOfStringsNumbersAndBooleans.find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => boolean, thisArg?: any): string | number | boolean; }
+>readonlyArrayOfStringsNumbersAndBooleans.find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => unknown, thisArg?: any): string | number | boolean; }
 >readonlyArrayOfStringsNumbersAndBooleans : readonly (string | number | boolean)[]
->find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => boolean, thisArg?: any): string | number | boolean; }
+>find : { <S extends string | number | boolean>(predicate: (this: void, value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => value is S, thisArg?: any): S; (predicate: (value: string | number | boolean, index: number, obj: readonly (string | number | boolean)[]) => unknown, thisArg?: any): string | number | boolean; }
 >isNumber : (x: any) => x is number
 
diff --git a/tests/baselines/reference/contextuallyTypedIife.types b/tests/baselines/reference/contextuallyTypedIife.types
index df0b788459476..4e6f9f71c923e 100644
--- a/tests/baselines/reference/contextuallyTypedIife.types
+++ b/tests/baselines/reference/contextuallyTypedIife.types
@@ -105,9 +105,9 @@
 >(...numbers) => numbers.every(n => n > 0) : (numbers_0: number, numbers_1: number, numbers_2: number) => boolean
 >numbers : [number, number, number]
 >numbers.every(n => n > 0) : boolean
->numbers.every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>numbers.every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >numbers : [number, number, number]
->every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >n => n > 0 : (n: number) => boolean
 >n : number
 >n > 0 : boolean
@@ -123,9 +123,9 @@
 >(...mixed) => mixed.every(n => !!n) : (mixed_0: number, mixed_1: string, mixed_2: string) => boolean
 >mixed : [number, string, string]
 >mixed.every(n => !!n) : boolean
->mixed.every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>mixed.every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => unknown, thisArg?: any) => boolean
 >mixed : [number, string, string]
->every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => unknown, thisArg?: any) => boolean
 >n => !!n : (n: string | number) => boolean
 >n : string | number
 >!!n : boolean
@@ -141,9 +141,9 @@
 >(...noNumbers) => noNumbers.some(n => n > 0) : () => boolean
 >noNumbers : []
 >noNumbers.some(n => n > 0) : boolean
->noNumbers.some : (callbackfn: (value: never, index: number, array: never[]) => boolean, thisArg?: any) => boolean
+>noNumbers.some : (callbackfn: (value: never, index: number, array: never[]) => unknown, thisArg?: any) => boolean
 >noNumbers : []
->some : (callbackfn: (value: never, index: number, array: never[]) => boolean, thisArg?: any) => boolean
+>some : (callbackfn: (value: never, index: number, array: never[]) => unknown, thisArg?: any) => boolean
 >n => n > 0 : (n: never) => boolean
 >n : never
 >n > 0 : boolean
diff --git a/tests/baselines/reference/contextuallyTypedIifeStrict.types b/tests/baselines/reference/contextuallyTypedIifeStrict.types
index e20c08a20debf..18ad0a1241f73 100644
--- a/tests/baselines/reference/contextuallyTypedIifeStrict.types
+++ b/tests/baselines/reference/contextuallyTypedIifeStrict.types
@@ -105,9 +105,9 @@
 >(...numbers) => numbers.every(n => n > 0) : (numbers_0: number, numbers_1: number, numbers_2: number) => boolean
 >numbers : [number, number, number]
 >numbers.every(n => n > 0) : boolean
->numbers.every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>numbers.every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >numbers : [number, number, number]
->every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >n => n > 0 : (n: number) => boolean
 >n : number
 >n > 0 : boolean
@@ -123,9 +123,9 @@
 >(...mixed) => mixed.every(n => !!n) : (mixed_0: number, mixed_1: string, mixed_2: string) => boolean
 >mixed : [number, string, string]
 >mixed.every(n => !!n) : boolean
->mixed.every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>mixed.every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => unknown, thisArg?: any) => boolean
 >mixed : [number, string, string]
->every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: string | number, index: number, array: (string | number)[]) => unknown, thisArg?: any) => boolean
 >n => !!n : (n: string | number) => boolean
 >n : string | number
 >!!n : boolean
@@ -141,9 +141,9 @@
 >(...noNumbers) => noNumbers.some(n => n > 0) : () => boolean
 >noNumbers : []
 >noNumbers.some(n => n > 0) : boolean
->noNumbers.some : (callbackfn: (value: never, index: number, array: never[]) => boolean, thisArg?: any) => boolean
+>noNumbers.some : (callbackfn: (value: never, index: number, array: never[]) => unknown, thisArg?: any) => boolean
 >noNumbers : []
->some : (callbackfn: (value: never, index: number, array: never[]) => boolean, thisArg?: any) => boolean
+>some : (callbackfn: (value: never, index: number, array: never[]) => unknown, thisArg?: any) => boolean
 >n => n > 0 : (n: never) => boolean
 >n : never
 >n > 0 : boolean
diff --git a/tests/baselines/reference/declarationEmitPromise.types b/tests/baselines/reference/declarationEmitPromise.types
index f545baeb443bb..56ff62f6e1d4e 100644
--- a/tests/baselines/reference/declarationEmitPromise.types
+++ b/tests/baselines/reference/declarationEmitPromise.types
@@ -26,14 +26,14 @@ export async function runSampleWorks<A, B, C, D, E>(
 >bluebird : typeof bluebird
 >all : bluebird<any>[]
 >[a, b, c, d, e].filter(el => !!el) : bluebird<A>[]
->[a, b, c, d, e].filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => any, thisArg?: any): bluebird<A>[]; }
+>[a, b, c, d, e].filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => unknown, thisArg?: any): bluebird<A>[]; }
 >[a, b, c, d, e] : bluebird<A>[]
 >a : bluebird<A>
 >b : bluebird<B>
 >c : bluebird<C>
 >d : bluebird<D>
 >e : bluebird<E>
->filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => any, thisArg?: any): bluebird<A>[]; }
+>filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => unknown, thisArg?: any): bluebird<A>[]; }
 >el => !!el : (el: bluebird<A>) => boolean
 >el : bluebird<A>
 >!!el : boolean
@@ -88,14 +88,14 @@ export async function runSampleBreaks<A, B, C, D, E>(
 >bluebird : typeof bluebird
 >all : bluebird<any>[]
 >[a, b, c, d, e].filter(el => !!el) : bluebird<A>[]
->[a, b, c, d, e].filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => any, thisArg?: any): bluebird<A>[]; }
+>[a, b, c, d, e].filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => unknown, thisArg?: any): bluebird<A>[]; }
 >[a, b, c, d, e] : bluebird<A>[]
 >a : bluebird<A>
 >b : bluebird<B>
 >c : bluebird<C>
 >d : bluebird<D>
 >e : bluebird<E>
->filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => any, thisArg?: any): bluebird<A>[]; }
+>filter : { <S extends bluebird<A>>(callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: bluebird<A>, index: number, array: bluebird<A>[]) => unknown, thisArg?: any): bluebird<A>[]; }
 >el => !!el : (el: bluebird<A>) => boolean
 >el : bluebird<A>
 >!!el : boolean
diff --git a/tests/baselines/reference/duplicateLocalVariable1.types b/tests/baselines/reference/duplicateLocalVariable1.types
index 4a7dcb41919a7..9ad7673412e18 100644
--- a/tests/baselines/reference/duplicateLocalVariable1.types
+++ b/tests/baselines/reference/duplicateLocalVariable1.types
@@ -41,9 +41,9 @@ export class TestRunner {
         return (arg1.every(function (val, index) { return val === arg2[index] }));
 >(arg1.every(function (val, index) { return val === arg2[index] })) : boolean
 >arg1.every(function (val, index) { return val === arg2[index] }) : boolean
->arg1.every : (callbackfn: (value: any, index: number, array: any[]) => boolean, thisArg?: any) => boolean
+>arg1.every : (callbackfn: (value: any, index: number, array: any[]) => unknown, thisArg?: any) => boolean
 >arg1 : any[]
->every : (callbackfn: (value: any, index: number, array: any[]) => boolean, thisArg?: any) => boolean
+>every : (callbackfn: (value: any, index: number, array: any[]) => unknown, thisArg?: any) => boolean
 >function (val, index) { return val === arg2[index] } : (val: any, index: number) => boolean
 >val : any
 >index : number
diff --git a/tests/baselines/reference/genericContextualTypes1.types b/tests/baselines/reference/genericContextualTypes1.types
index fb97b190d659e..e52f26e73d919 100644
--- a/tests/baselines/reference/genericContextualTypes1.types
+++ b/tests/baselines/reference/genericContextualTypes1.types
@@ -155,9 +155,9 @@ const arrayFilter = <T>(f: (x: T) => boolean) => (a: T[]) => a.filter(f);
 >(a: T[]) => a.filter(f) : (a: T[]) => T[]
 >a : T[]
 >a.filter(f) : T[]
->a.filter : { <S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[]; }
+>a.filter : { <S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[]; }
 >a : T[]
->filter : { <S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[]; }
+>filter : { <S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[]; }
 >f : (x: T) => boolean
 
 const f20: (a: string[]) => number[] = arrayMap(x => x.length);
diff --git a/tests/baselines/reference/genericMethodOverspecialization.types b/tests/baselines/reference/genericMethodOverspecialization.types
index dbc3a62653c2d..23475f966d684 100644
--- a/tests/baselines/reference/genericMethodOverspecialization.types
+++ b/tests/baselines/reference/genericMethodOverspecialization.types
@@ -47,9 +47,9 @@ var elements = names.map(function (name) {
 var xxx = elements.filter(function (e) {
 >xxx : HTMLElement[]
 >elements.filter(function (e) {    return !e.isDisabled;}) : HTMLElement[]
->elements.filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => any, thisArg?: any): HTMLElement[]; }
+>elements.filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => unknown, thisArg?: any): HTMLElement[]; }
 >elements : HTMLElement[]
->filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => any, thisArg?: any): HTMLElement[]; }
+>filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => unknown, thisArg?: any): HTMLElement[]; }
 >function (e) {    return !e.isDisabled;} : (e: HTMLElement) => boolean
 >e : HTMLElement
 
diff --git a/tests/baselines/reference/parserharness.types b/tests/baselines/reference/parserharness.types
index eb5a2884edf06..5fde386f90acf 100644
--- a/tests/baselines/reference/parserharness.types
+++ b/tests/baselines/reference/parserharness.types
@@ -3931,9 +3931,9 @@ module Harness {
                                 if (!matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type))) {
 >!matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type)) : boolean
 >matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type)) : boolean
->matchingIdentifiers.some : (callbackfn: (value: Type, index: number, array: Type[]) => boolean, thisArg?: any) => boolean
+>matchingIdentifiers.some : (callbackfn: (value: Type, index: number, array: Type[]) => unknown, thisArg?: any) => boolean
 >matchingIdentifiers : Type[]
->some : (callbackfn: (value: Type, index: number, array: Type[]) => boolean, thisArg?: any) => boolean
+>some : (callbackfn: (value: Type, index: number, array: Type[]) => unknown, thisArg?: any) => boolean
 >value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type) : (value: Type) => boolean
 >value : Type
 >(value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type) : boolean
@@ -4020,9 +4020,9 @@ module Harness {
                                         if (!matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type))) {
 >!matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type)) : boolean
 >matchingIdentifiers.some(value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type)) : boolean
->matchingIdentifiers.some : (callbackfn: (value: Type, index: number, array: Type[]) => boolean, thisArg?: any) => boolean
+>matchingIdentifiers.some : (callbackfn: (value: Type, index: number, array: Type[]) => unknown, thisArg?: any) => boolean
 >matchingIdentifiers : Type[]
->some : (callbackfn: (value: Type, index: number, array: Type[]) => boolean, thisArg?: any) => boolean
+>some : (callbackfn: (value: Type, index: number, array: Type[]) => unknown, thisArg?: any) => boolean
 >value => (value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type) : (value: Type) => boolean
 >value : Type
 >(value.identifier === foundValue.identifier) && (value.code === foundValue.code) && (value.type === foundValue.type) : boolean
diff --git a/tests/baselines/reference/restInvalidArgumentType.types b/tests/baselines/reference/restInvalidArgumentType.types
index 54af9099c311d..d88ee53796aac 100644
--- a/tests/baselines/reference/restInvalidArgumentType.types
+++ b/tests/baselines/reference/restInvalidArgumentType.types
@@ -71,7 +71,7 @@ function f<T extends { b: string }>(p1: T, p2: T[]) {
 >p1 : T
 
     var {...r2} = p2;   // OK
->r2 : { [n: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
+>r2 : { [n: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
 >p2 : T[]
 
     var {...r3} = t;   // Error, generic type paramter
diff --git a/tests/baselines/reference/restParameterWithBindingPattern3.types b/tests/baselines/reference/restParameterWithBindingPattern3.types
index 1385bde0c3fae..b98f0cdd367d7 100644
--- a/tests/baselines/reference/restParameterWithBindingPattern3.types
+++ b/tests/baselines/reference/restParameterWithBindingPattern3.types
@@ -31,5 +31,5 @@ function e(...{0: a = 1, 1: b = true, ...rest: rest}: [boolean, string, number])
 >b : string
 >true : true
 >rest : any
->rest : { [n: number]: string | number | boolean; 0: boolean; 1: string; 2: number; length: 3; toString(): string; toLocaleString(): string; pop(): string | number | boolean; push(...items: (string | number | boolean)[]): number; concat(...items: ConcatArray<string | number | boolean>[]): (string | number | boolean)[]; concat(...items: (string | number | boolean | ConcatArray<string | number | boolean>)[]): (string | number | boolean)[]; join(separator?: string): string; reverse(): (string | number | boolean)[]; shift(): string | number | boolean; slice(start?: number, end?: number): (string | number | boolean)[]; sort(compareFn?: (a: string | number | boolean, b: string | number | boolean) => number): [boolean, string, number]; splice(start: number, deleteCount?: number): (string | number | boolean)[]; splice(start: number, deleteCount: number, ...items: (string | number | boolean)[]): (string | number | boolean)[]; unshift(...items: (string | number | boolean)[]): number; indexOf(searchElement: string | number | boolean, fromIndex?: number): number; lastIndexOf(searchElement: string | number | boolean, fromIndex?: number): number; every(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => boolean, thisArg?: any): boolean; some(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => boolean, thisArg?: any): boolean; forEach(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => U, thisArg?: any): U[]; filter<S extends string | number | boolean>(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => any, thisArg?: any): (string | number | boolean)[]; reduce(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean): string | number | boolean; reduce(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean, initialValue: string | number | boolean): string | number | boolean; reduce<U>(callbackfn: (previousValue: U, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean): string | number | boolean; reduceRight(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean, initialValue: string | number | boolean): string | number | boolean; reduceRight<U>(callbackfn: (previousValue: U, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => U, initialValue: U): U; }
+>rest : { [n: number]: string | number | boolean; 0: boolean; 1: string; 2: number; length: 3; toString(): string; toLocaleString(): string; pop(): string | number | boolean; push(...items: (string | number | boolean)[]): number; concat(...items: ConcatArray<string | number | boolean>[]): (string | number | boolean)[]; concat(...items: (string | number | boolean | ConcatArray<string | number | boolean>)[]): (string | number | boolean)[]; join(separator?: string): string; reverse(): (string | number | boolean)[]; shift(): string | number | boolean; slice(start?: number, end?: number): (string | number | boolean)[]; sort(compareFn?: (a: string | number | boolean, b: string | number | boolean) => number): [boolean, string, number]; splice(start: number, deleteCount?: number): (string | number | boolean)[]; splice(start: number, deleteCount: number, ...items: (string | number | boolean)[]): (string | number | boolean)[]; unshift(...items: (string | number | boolean)[]): number; indexOf(searchElement: string | number | boolean, fromIndex?: number): number; lastIndexOf(searchElement: string | number | boolean, fromIndex?: number): number; every(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => unknown, thisArg?: any): boolean; some(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => unknown, thisArg?: any): boolean; forEach(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => U, thisArg?: any): U[]; filter<S extends string | number | boolean>(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: string | number | boolean, index: number, array: (string | number | boolean)[]) => unknown, thisArg?: any): (string | number | boolean)[]; reduce(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean): string | number | boolean; reduce(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean, initialValue: string | number | boolean): string | number | boolean; reduce<U>(callbackfn: (previousValue: U, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean): string | number | boolean; reduceRight(callbackfn: (previousValue: string | number | boolean, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => string | number | boolean, initialValue: string | number | boolean): string | number | boolean; reduceRight<U>(callbackfn: (previousValue: U, currentValue: string | number | boolean, currentIndex: number, array: (string | number | boolean)[]) => U, initialValue: U): U; }
 
diff --git a/tests/baselines/reference/spreadInvalidArgumentType.types b/tests/baselines/reference/spreadInvalidArgumentType.types
index 6828d557d0a85..8a833c966ff97 100644
--- a/tests/baselines/reference/spreadInvalidArgumentType.types
+++ b/tests/baselines/reference/spreadInvalidArgumentType.types
@@ -73,8 +73,8 @@ function f<T extends { b: string }>(p1: T, p2: T[]) {
 >p1 : T
 
     var o2 = { ...p2 };  // OK
->o2 : { [x: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
->{ ...p2 } : { [n: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => boolean, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => any, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
+>o2 : { [x: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
+>{ ...p2 } : { [n: number]: T; length: number; toString(): string; toLocaleString(): string; pop(): T; push(...items: T[]): number; concat(...items: ConcatArray<T>[]): T[]; concat(...items: (T | ConcatArray<T>)[]): T[]; join(separator?: string): string; reverse(): T[]; shift(): T; slice(start?: number, end?: number): T[]; sort(compareFn?: (a: T, b: T) => number): T[]; splice(start: number, deleteCount?: number): T[]; splice(start: number, deleteCount: number, ...items: T[]): T[]; unshift(...items: T[]): number; indexOf(searchElement: T, fromIndex?: number): number; lastIndexOf(searchElement: T, fromIndex?: number): number; every(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; some(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): boolean; forEach(callbackfn: (value: T, index: number, array: T[]) => void, thisArg?: any): void; map<U>(callbackfn: (value: T, index: number, array: T[]) => U, thisArg?: any): U[]; filter<S extends T>(callbackfn: (value: T, index: number, array: T[]) => value is S, thisArg?: any): S[]; filter(callbackfn: (value: T, index: number, array: T[]) => unknown, thisArg?: any): T[]; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T): T; reduceRight(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue: T): T; reduceRight<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }
 >p2 : T[]
 
     var o3 = { ...t };   // OK, generic type paramter
diff --git a/tests/baselines/reference/targetTypeArgs.types b/tests/baselines/reference/targetTypeArgs.types
index 84985316aa2d6..980592d4d576c 100644
--- a/tests/baselines/reference/targetTypeArgs.types
+++ b/tests/baselines/reference/targetTypeArgs.types
@@ -31,11 +31,11 @@ foo(function(x) { x });
 
 ["hello"].every(function(v,i,a) {return true;});
 >["hello"].every(function(v,i,a) {return true;}) : boolean
->["hello"].every : (callbackfn: (value: string, index: number, array: string[]) => boolean, thisArg?: any) => boolean
+>["hello"].every : (callbackfn: (value: string, index: number, array: string[]) => unknown, thisArg?: any) => boolean
 >["hello"] : string[]
 >"hello" : "hello"
->every : (callbackfn: (value: string, index: number, array: string[]) => boolean, thisArg?: any) => boolean
->function(v,i,a) {return true;} : (v: string, i: number, a: string[]) => true
+>every : (callbackfn: (value: string, index: number, array: string[]) => unknown, thisArg?: any) => boolean
+>function(v,i,a) {return true;} : (v: string, i: number, a: string[]) => boolean
 >v : string
 >i : number
 >a : string[]
@@ -43,11 +43,11 @@ foo(function(x) { x });
 
 [1].every(function(v,i,a) {return true;});
 >[1].every(function(v,i,a) {return true;}) : boolean
->[1].every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>[1].every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >[1] : number[]
 >1 : 1
->every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
->function(v,i,a) {return true;} : (v: number, i: number, a: number[]) => true
+>every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
+>function(v,i,a) {return true;} : (v: number, i: number, a: number[]) => boolean
 >v : number
 >i : number
 >a : number[]
@@ -55,11 +55,11 @@ foo(function(x) { x });
 
 [1].every(function(v,i,a) {return true;});
 >[1].every(function(v,i,a) {return true;}) : boolean
->[1].every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
+>[1].every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
 >[1] : number[]
 >1 : 1
->every : (callbackfn: (value: number, index: number, array: number[]) => boolean, thisArg?: any) => boolean
->function(v,i,a) {return true;} : (v: number, i: number, a: number[]) => true
+>every : (callbackfn: (value: number, index: number, array: number[]) => unknown, thisArg?: any) => boolean
+>function(v,i,a) {return true;} : (v: number, i: number, a: number[]) => boolean
 >v : number
 >i : number
 >a : number[]
@@ -67,11 +67,11 @@ foo(function(x) { x });
 
 ["s"].every(function(v,i,a) {return true;});
 >["s"].every(function(v,i,a) {return true;}) : boolean
->["s"].every : (callbackfn: (value: string, index: number, array: string[]) => boolean, thisArg?: any) => boolean
+>["s"].every : (callbackfn: (value: string, index: number, array: string[]) => unknown, thisArg?: any) => boolean
 >["s"] : string[]
 >"s" : "s"
->every : (callbackfn: (value: string, index: number, array: string[]) => boolean, thisArg?: any) => boolean
->function(v,i,a) {return true;} : (v: string, i: number, a: string[]) => true
+>every : (callbackfn: (value: string, index: number, array: string[]) => unknown, thisArg?: any) => boolean
+>function(v,i,a) {return true;} : (v: string, i: number, a: string[]) => boolean
 >v : string
 >i : number
 >a : string[]
diff --git a/tests/baselines/reference/typeInferenceTypePredicate2.types b/tests/baselines/reference/typeInferenceTypePredicate2.types
index d0f36101e1243..a0c05e4a4d0ee 100644
--- a/tests/baselines/reference/typeInferenceTypePredicate2.types
+++ b/tests/baselines/reference/typeInferenceTypePredicate2.types
@@ -3,7 +3,7 @@
 >[true, true, false, null]    .filter((thing): thing is boolean => thing !== null)    .map(thing => thing.toString()) : string[]
 >[true, true, false, null]    .filter((thing): thing is boolean => thing !== null)    .map : <U>(callbackfn: (value: boolean, index: number, array: boolean[]) => U, thisArg?: any) => U[]
 >[true, true, false, null]    .filter((thing): thing is boolean => thing !== null) : boolean[]
->[true, true, false, null]    .filter : { <S extends boolean>(callbackfn: (value: boolean, index: number, array: boolean[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: boolean, index: number, array: boolean[]) => any, thisArg?: any): boolean[]; }
+>[true, true, false, null]    .filter : { <S extends boolean>(callbackfn: (value: boolean, index: number, array: boolean[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: boolean, index: number, array: boolean[]) => unknown, thisArg?: any): boolean[]; }
 >[true, true, false, null] : boolean[]
 >true : true
 >true : true
@@ -11,7 +11,7 @@
 >null : null
 
     .filter((thing): thing is boolean => thing !== null)
->filter : { <S extends boolean>(callbackfn: (value: boolean, index: number, array: boolean[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: boolean, index: number, array: boolean[]) => any, thisArg?: any): boolean[]; }
+>filter : { <S extends boolean>(callbackfn: (value: boolean, index: number, array: boolean[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: boolean, index: number, array: boolean[]) => unknown, thisArg?: any): boolean[]; }
 >(thing): thing is boolean => thing !== null : (thing: boolean) => thing is boolean
 >thing : boolean
 >thing !== null : boolean
diff --git a/tests/baselines/reference/unknownSymbolOffContextualType1.types b/tests/baselines/reference/unknownSymbolOffContextualType1.types
index 04321b94dadd8..8ad87586580ff 100644
--- a/tests/baselines/reference/unknownSymbolOffContextualType1.types
+++ b/tests/baselines/reference/unknownSymbolOffContextualType1.types
@@ -35,9 +35,9 @@ function getMaxWidth(elementNames: string[]) {
     var enabled = elements.filter(function (e) {
 >enabled : HTMLElement[]
 >elements.filter(function (e) {        return !e.isDisabled;    }) : HTMLElement[]
->elements.filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => any, thisArg?: any): HTMLElement[]; }
+>elements.filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => unknown, thisArg?: any): HTMLElement[]; }
 >elements : HTMLElement[]
->filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => any, thisArg?: any): HTMLElement[]; }
+>filter : { <S extends HTMLElement>(callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => value is S, thisArg?: any): S[]; (callbackfn: (value: HTMLElement, index: number, array: HTMLElement[]) => unknown, thisArg?: any): HTMLElement[]; }
 >function (e) {        return !e.isDisabled;    } : (e: HTMLElement) => boolean
 >e : HTMLElement