diff --git a/Tools/autogsdoc.m b/Tools/autogsdoc.m
index b1ffba75b..6d5b099dc 100644
--- a/Tools/autogsdoc.m
+++ b/Tools/autogsdoc.m
@@ -2222,7 +2222,7 @@ standard PropertyList format (not the XML format of OS X), using
 			stringByAppendingPathComponent: @"index.html"];
 		      if ([d writeToFile: s atomically: YES])
 			{
-			  NSLog(@"Sorry unable to write %@ to %s", htmlfile, s);
+			  NSLog(@"Sorry unable to write %@ to %@", htmlfile, s);
 			}
 		    }
 		}