diff --git a/Source/NSObject.m b/Source/NSObject.m
index fa5a75ed8..c26a95f19 100644
--- a/Source/NSObject.m
+++ b/Source/NSObject.m
@@ -2104,12 +2104,6 @@ - (BOOL) respondsToSelector: (SEL)aSelector
 
   if (aSelector == 0)
     {
-      if (GSPrivateDefaultsFlag(GSMacOSXCompatible))
-	{
-	  [NSException raise: NSInvalidArgumentException
-		    format: @"%@ null selector given",
-	    NSStringFromSelector(_cmd)];
-	}
       return NO;
     }