diff --git a/support/kconfig/util.c b/support/kconfig/util.c
index 8665f5bb89..c2e7979ac1 100644
--- a/support/kconfig/util.c
+++ b/support/kconfig/util.c
@@ -35,7 +35,7 @@ struct file *file_lookup(const char *name)
 int file_write_dep(const char *name)
 {
 	char *str;
-	char buf[PATH_MAX+20], buf2[PATH_MAX+1], dir[PATH_MAX+1];
+	char buf[PATH_MAX+20], buf2[PATH_MAX+20], dir[PATH_MAX+1];
 	struct symbol *sym, *env_sym;
 	struct expr *e;
 	struct file *file;