diff --git a/src/type/directives.js b/src/type/directives.js
index d9207f1637..8f2596d645 100644
--- a/src/type/directives.js
+++ b/src/type/directives.js
@@ -190,10 +190,6 @@ export const specifiedDirectives: $ReadOnlyArray<*> = [
 export function isSpecifiedDirective(directive: mixed): boolean %checks {
   return (
     isDirective(directive) &&
-    // Would prefer to use specifiedDirectives.some(), however %checks needs
-    // a simple expression.
-    (directive.name === GraphQLIncludeDirective.name ||
-      directive.name === GraphQLSkipDirective.name ||
-      directive.name === GraphQLDeprecatedDirective.name)
+    specifiedDirectives.some(({ name }) => name === directive.name)
   );
 }
diff --git a/src/type/introspection.js b/src/type/introspection.js
index 731e5412d9..aa4615874f 100644
--- a/src/type/introspection.js
+++ b/src/type/introspection.js
@@ -487,15 +487,6 @@ export const introspectionTypes: $ReadOnlyArray<*> = [
 export function isIntrospectionType(type: mixed): boolean %checks {
   return (
     isNamedType(type) &&
-    // Would prefer to use introspectionTypes.some(), however %checks needs
-    // a simple expression.
-    (type.name === __Schema.name ||
-      type.name === __Directive.name ||
-      type.name === __DirectiveLocation.name ||
-      type.name === __Type.name ||
-      type.name === __Field.name ||
-      type.name === __InputValue.name ||
-      type.name === __EnumValue.name ||
-      type.name === __TypeKind.name)
+    introspectionTypes.some(({ name }) => type.name === name)
   );
 }
diff --git a/src/type/scalars.js b/src/type/scalars.js
index e6ed82f26f..b7b6d7b2e8 100644
--- a/src/type/scalars.js
+++ b/src/type/scalars.js
@@ -256,12 +256,6 @@ export const specifiedScalarTypes: $ReadOnlyArray<*> = [
 export function isSpecifiedScalarType(type: mixed): boolean %checks {
   return (
     isScalarType(type) &&
-    // Would prefer to use specifiedScalarTypes.some(), however %checks needs
-    // a simple expression.
-    (type.name === GraphQLString.name ||
-      type.name === GraphQLInt.name ||
-      type.name === GraphQLFloat.name ||
-      type.name === GraphQLBoolean.name ||
-      type.name === GraphQLID.name)
+    specifiedScalarTypes.some(({ name }) => type.name === name)
   );
 }