diff --git a/Foundation/NSDictionary.swift b/Foundation/NSDictionary.swift
index 56e8b00752..ac03e8bbd0 100644
--- a/Foundation/NSDictionary.swift
+++ b/Foundation/NSDictionary.swift
@@ -148,7 +148,7 @@ open class NSDictionary : NSObject, NSCopying, NSMutableCopying, NSSecureCoding,
             keyedArchiver._encodeArrayOfObjects(self.allKeys._nsObject, forKey:"NS.keys")
             keyedArchiver._encodeArrayOfObjects(self.allValues._nsObject, forKey:"NS.objects")
         } else {
-            NSUnimplemented()
+            NSUnsupported()
         }
     }