diff --git a/alsactl/lock.c b/alsactl/lock.c
index d34d013..fce208b 100644
--- a/alsactl/lock.c
+++ b/alsactl/lock.c
@@ -35,7 +35,7 @@ static int state_lock_(const char *file, int lock, int timeout)
 	int fd = -1, err = 0;
 	struct flock lck;
 	struct stat st;
-	char lcktxt[11];
+	char lcktxt[12];
 	char *nfile;
 
 	if (!do_lock)