diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 994fb1d765330..d39613e515194 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -60,7 +60,7 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
 
 /**
   * Computes a new string in which certain characters have been replaced by a hexadecimal escape sequence.
diff --git a/tests/baselines/reference/1.0lib-noErrors.js b/tests/baselines/reference/1.0lib-noErrors.js
index ade0f4bf903b9..3dac98d9e5647 100644
--- a/tests/baselines/reference/1.0lib-noErrors.js
+++ b/tests/baselines/reference/1.0lib-noErrors.js
@@ -78,7 +78,7 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
 
 interface PropertyDescriptor {
     configurable?: boolean;
@@ -1141,7 +1141,7 @@ declare var Array: {
     <T>(...items: T[]): T[];
     isArray(arg: any): boolean;
     prototype: Array<any>;
-}
+}

 
 //// [1.0lib-noErrors.js]
 /* *****************************************************************************
diff --git a/tests/baselines/reference/1.0lib-noErrors.symbols b/tests/baselines/reference/1.0lib-noErrors.symbols
index adedbdb9aa2dc..d67952e201c98 100644
--- a/tests/baselines/reference/1.0lib-noErrors.symbols
+++ b/tests/baselines/reference/1.0lib-noErrors.symbols
@@ -98,12 +98,12 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
 >encodeURIComponent : Symbol(encodeURIComponent, Decl(1.0lib-noErrors.ts, 73, 48))
 >uriComponent : Symbol(uriComponent, Decl(1.0lib-noErrors.ts, 79, 36))
 
 interface PropertyDescriptor {
->PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 66))
+>PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 85))
 
     configurable?: boolean;
 >configurable : Symbol(PropertyDescriptor.configurable, Decl(1.0lib-noErrors.ts, 81, 30))
@@ -130,7 +130,7 @@ interface PropertyDescriptorMap {
 
     [s: string]: PropertyDescriptor;
 >s : Symbol(s, Decl(1.0lib-noErrors.ts, 91, 5))
->PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 66))
+>PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 85))
 }
 
 interface Object {
@@ -217,7 +217,7 @@ declare var Object: {
 >getOwnPropertyDescriptor : Symbol(getOwnPropertyDescriptor, Decl(1.0lib-noErrors.ts, 141, 32))
 >o : Symbol(o, Decl(1.0lib-noErrors.ts, 149, 29))
 >p : Symbol(p, Decl(1.0lib-noErrors.ts, 149, 36))
->PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 66))
+>PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 85))
 
     /** 
       * Returns the names of the own properties of an object. The own properties of an object are those that are defined directly 
@@ -250,7 +250,7 @@ declare var Object: {
 >o : Symbol(o, Decl(1.0lib-noErrors.ts, 171, 19))
 >p : Symbol(p, Decl(1.0lib-noErrors.ts, 171, 26))
 >attributes : Symbol(attributes, Decl(1.0lib-noErrors.ts, 171, 37))
->PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 66))
+>PropertyDescriptor : Symbol(PropertyDescriptor, Decl(1.0lib-noErrors.ts, 79, 85))
 
     /**
       * Adds one or more properties to an object, and/or modifies attributes of existing properties. 
@@ -2084,3 +2084,4 @@ declare var Array: {
 >prototype : Symbol(prototype, Decl(1.0lib-noErrors.ts, 1140, 31))
 >Array : Symbol(Array, Decl(1.0lib-noErrors.ts, 973, 23), Decl(1.0lib-noErrors.ts, 1133, 11))
 }
+
diff --git a/tests/baselines/reference/1.0lib-noErrors.types b/tests/baselines/reference/1.0lib-noErrors.types
index 1d9c67834e702..91e5fdc7b7356 100644
--- a/tests/baselines/reference/1.0lib-noErrors.types
+++ b/tests/baselines/reference/1.0lib-noErrors.types
@@ -98,9 +98,9 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
->encodeURIComponent : (uriComponent: string) => string
->uriComponent : string
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
+>encodeURIComponent : (uriComponent: string | number | boolean) => string
+>uriComponent : string | number | boolean
 
 interface PropertyDescriptor {
     configurable?: boolean;
@@ -1911,3 +1911,4 @@ declare var Array: {
     prototype: Array<any>;
 >prototype : any[]
 }
+
diff --git a/tests/baselines/reference/parserRegularExpression4.types b/tests/baselines/reference/parserRegularExpression4.types
index 1a0db05a48e48..1af56c7a24fc6 100644
--- a/tests/baselines/reference/parserRegularExpression4.types
+++ b/tests/baselines/reference/parserRegularExpression4.types
@@ -61,7 +61,7 @@ if (Ca.test(c.href) || Ba.test(c.href) && /(\\?|&)adurl=/.test(c.href) && !/(\\?
 >"&q=" + encodeURIComponent(W("q") || W("as_q") || A) : string
 >"&q=" : "&q="
 >encodeURIComponent(W("q") || W("as_q") || A) : string
->encodeURIComponent : (uriComponent: string) => string
+>encodeURIComponent : (uriComponent: string | number | boolean) => string
 >W("q") || W("as_q") || A : any
 >W("q") || W("as_q") : any
 >W("q") : any
diff --git a/tests/cases/conformance/decorators/1.0lib-noErrors.ts b/tests/cases/conformance/decorators/1.0lib-noErrors.ts
index 6966e3e70d07d..391c0926a82b7 100644
--- a/tests/cases/conformance/decorators/1.0lib-noErrors.ts
+++ b/tests/cases/conformance/decorators/1.0lib-noErrors.ts
@@ -78,7 +78,7 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
 
 interface PropertyDescriptor {
     configurable?: boolean;
@@ -1141,4 +1141,4 @@ declare var Array: {
     <T>(...items: T[]): T[];
     isArray(arg: any): boolean;
     prototype: Array<any>;
-}
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/tests/lib/lib.d.ts b/tests/lib/lib.d.ts
index ad17bec673e95..5f089bb3c82eb 100644
--- a/tests/lib/lib.d.ts
+++ b/tests/lib/lib.d.ts
@@ -77,7 +77,7 @@ declare function encodeURI(uri: string): string;
   * Encodes a text string as a valid component of a Uniform Resource Identifier (URI).
   * @param uriComponent A value representing an encoded URI component.
   */
-declare function encodeURIComponent(uriComponent: string): string;
+declare function encodeURIComponent(uriComponent: string | number | boolean): string;
 
 /**
   * Computes a new string in which certain characters have been replaced by a hexadecimal escape sequence.