diff --git a/ChangeLog b/ChangeLog
index f8840f7fd..ac3efd462 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jul  1 14:00:00 1999  Richard Frith-Macdonald <richard@brainstorm.co.uk>
+
+	Patch by Kai Henningsen to improve debug slightly.
+	* Source/NSObject.m: improved exception messages.
+
 Wed Jun 30 22:30:00 1999  Richard Frith-Macdonald <richard@brainstorm.co.uk>
 
 	* Source/NSArray.m: Tidied for garbage collection.
diff --git a/Source/NSObject.m b/Source/NSObject.m
index b708dcdd7..02c691548 100644
--- a/Source/NSObject.m
+++ b/Source/NSObject.m
@@ -530,7 +530,7 @@ static BOOL double_release_check_enabled = NO;
 - free
 {
   [NSException raise: NSGenericException
-	       format: @"Use `dealloc' instead of `free'."];
+	       format: @"Use `dealloc' instead of `free' for %@.", self];
   return nil;
 }
 
@@ -1078,7 +1078,7 @@ static BOOL double_release_check_enabled = NO;
 {
   [NSException
     raise: NSGenericException
-    format: @"method %s not implemented", sel_get_name(aSel)];
+    format: @"method %s not implemented in %s", sel_get_name(aSel), object_get_class_name(self)];
   return nil;
 }
 
@@ -1189,7 +1189,7 @@ static BOOL double_release_check_enabled = NO;
 {
   [NSException
     raise: NSGenericException
-    format: @"subclass should override %s", sel_get_name(aSel)];
+    format: @"subclass %s should override %s", object_get_class_name(self), sel_get_name(aSel)];
   return nil;
 }