diff --git a/ChangeLog b/ChangeLog
index 4352b90ea..d7ac1b22c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2000-11-09 Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSPort.m: ([-setDelegate:]) corrected assertion to allow
+	delegate to be set to nil.  Bug reported by cornils@mail.desy.de
+
 2000-11-08 Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/GSString.m: ([GSMutableString substringWithRange:]) fix to
diff --git a/Source/NSPort.m b/Source/NSPort.m
index 723b51cc0..25cef27a1 100644
--- a/Source/NSPort.m
+++ b/Source/NSPort.m
@@ -169,7 +169,8 @@ Class	NSPort_concrete_class;
 
 - (void) setDelegate: (id) anObject
 {
-  NSAssert([anObject respondsToSelector: @selector(handlePortMessage:)],
+  NSAssert(anObject == nil
+    || [anObject respondsToSelector: @selector(handlePortMessage:)],
     NSInvalidArgumentException);
   _delegate = anObject;
 }