| Index: src/collection.js | 
| diff --git a/src/collection.js b/src/collection.js | 
| index 4a73ff5d7fa716a145dc77dcf0a506239bb3a3be..c05dcd5249be6e6fc213fa99bf06cd26c21d7838 100644 | 
| --- a/src/collection.js | 
| +++ b/src/collection.js | 
| @@ -102,7 +102,7 @@ function SetConstructor(iterable) { | 
| if (!IS_NULL_OR_UNDEFINED(iterable)) { | 
| var adder = this.add; | 
| if (!IS_SPEC_FUNCTION(adder)) { | 
| -      throw MakeTypeError('property_not_function', ['add', this]); | 
| +      throw MakeTypeError(kPropertyNotFunction, ['add', this]); | 
| } | 
|  | 
| for (var value of iterable) { | 
| @@ -268,7 +268,7 @@ function MapConstructor(iterable) { | 
| if (!IS_NULL_OR_UNDEFINED(iterable)) { | 
| var adder = this.set; | 
| if (!IS_SPEC_FUNCTION(adder)) { | 
| -      throw MakeTypeError('property_not_function', ['set', this]); | 
| +      throw MakeTypeError(kPropertyNotFunction, ['set', this]); | 
| } | 
|  | 
| for (var nextItem of iterable) { | 
|  |