--- preproc.c	2008-02-19 20:08:57.000000000 +0100
+++ preproc.c	2008-04-15 08:51:51.526780000 +0200
@@ -1074,7 +1074,7 @@
         }
 
         for (r = p, s = ourcopy; *r; r++) {
-	    if (r > p+MAX_KEYWORD)
+	    if (r >= p+MAX_KEYWORD)
 		return tokval->t_type = TOKEN_ID; /* Not a keyword */
             *s++ = tolower(*r);
 	}