diff --git a/apps/app_voicemail.c b/apps/app_voicemail.c
index 6f6a932863..dca093d43d 100644
--- a/apps/app_voicemail.c
+++ b/apps/app_voicemail.c
@@ -1744,6 +1744,7 @@ static int open_mailbox(struct vm_state *vms, struct ast_vm_user *vmu, int box)
 		ast_log(LOG_WARNING, "The code expects the old messages to be checked first, fix the code.\n");
 	}
 	if (vm_allocate_dh(vms, vmu, box == 0 ? vms->vmArrayIndex + vms->oldmessages : vms->lastmsg)) {
+		ast_mutex_unlock(&vms->lock);
 		return -1;
 	}
 
@@ -5969,7 +5970,7 @@ static int open_mailbox(struct vm_state *vms, struct ast_vm_user *vmu,int box)
 
 	/* for local storage, checks directory for messages up to maxmsg limit */
 	last_msg = last_message_index(vmu, vms->curdir);
-	if (last_msg < 0)
+	if (last_msg < -1)
 		return last_msg;
 	else if (vms->lastmsg != last_msg)
 	{