diff --git a/winsup/cygwin/regex/regcomp.c b/winsup/cygwin/regex/regcomp.c
index 59da896a9..418e24a90 100644
--- a/winsup/cygwin/regex/regcomp.c
+++ b/winsup/cygwin/regex/regcomp.c
@@ -336,7 +336,7 @@ regcomp_internal(regex_t * __restrict preg,
 		computejumps(p, g);
 		computematchjumps(p, g);
 		if(g->matchjump == NULL && g->charjump != NULL) {
-			free(g->charjump);
+			free(&g->charjump[CHAR_MIN]);
 			g->charjump = NULL;
 		}
 	}