diff --git a/spec/core/asymmetricEqualityTesterArgCompatShimSpec.js b/spec/core/asymmetricEqualityTesterArgCompatShimSpec.js
index 34186c12..4d878716 100644
--- a/spec/core/asymmetricEqualityTesterArgCompatShimSpec.js
+++ b/spec/core/asymmetricEqualityTesterArgCompatShimSpec.js
@@ -66,7 +66,6 @@ describe('asymmetricEqualityTesterArgCompatShim', function() {
         'flatMap',
         'includes',
         'keys',
-        'toSource',
         'values'
       ],
       shim = jasmineUnderTest.asymmetricEqualityTesterArgCompatShim({}, []),