@@ -16,25 +16,25 @@
  */
 
 #import <Foundation/NSDictionary.h>
 
 #import "OFNSDictionary.h"
+#import "OFNSEnumerator.h"
 
 #import "NSBridging.h"
 #import "OFBridging.h"
 
-#import "OFInitializationFailedException.h"
+#import "OFInvalidArgumentException.h"
 
 @implementation OFNSDictionary
 - (instancetype)initWithNSDictionary: (NSDictionary *)dictionary
 {
 	self = [super init];
 
 	@try {
 		if (dictionary == nil)
-			@throw [OFInitializationFailedException
-			    exceptionWithClass: self.class];
+			@throw [OFInvalidArgumentException exception];
 
 		_dictionary = [dictionary retain];
 	} @catch (id e) {
 		[self release];
 		@throw e;
@@ -67,6 +67,12 @@
 
 - (size_t)count
 {
 	return _dictionary.count;
 }
+
+- (OFEnumerator *)keyEnumerator
+{
+	return [[[OFNSEnumerator alloc]
+	    initWithNSEnumerator: [_dictionary keyEnumerator]] autorelease];
+}
 @end