diff --git a/Tools/autogsdoc.m b/Tools/autogsdoc.m
index 6d5b099dc..360c63fd5 100644
--- a/Tools/autogsdoc.m
+++ b/Tools/autogsdoc.m
@@ -2220,7 +2220,7 @@ standard PropertyList format (not the XML format of OS X), using
 
 		      s = [documentationDirectory
 			stringByAppendingPathComponent: @"index.html"];
-		      if ([d writeToFile: s atomically: YES])
+		      if ([d writeToFile: s atomically: YES] == NO)
 			{
 			  NSLog(@"Sorry unable to write %@ to %@", htmlfile, s);
 			}