diff --git a/gatchat/gatchat.c b/gatchat/gatchat.c
index f3bd3ec6..218f5921 100644
--- a/gatchat/gatchat.c
+++ b/gatchat/gatchat.c
@@ -1314,7 +1314,7 @@ GAtChat *g_at_chat_clone(GAtChat *clone)
 GAtChat *g_at_chat_set_slave(GAtChat *chat, GAtChat *slave)
 {
 	if (chat == NULL)
-		return;
+		return NULL;
 
 	if (chat->slave != NULL)
 		g_at_chat_unref(chat->slave);