diff --git a/src/wayland-client.c b/src/wayland-client.c
index c007f4c1..625cd760 100644
--- a/src/wayland-client.c
+++ b/src/wayland-client.c
@@ -141,7 +141,8 @@ wl_proxy_create(struct wl_proxy *factory, const struct wl_interface *interface)
 	return proxy;
 }
 
-WL_EXPORT struct wl_proxy *
+/* The caller should hold the display lock */
+static struct wl_proxy *
 wl_proxy_create_for_id(struct wl_proxy *factory,
 		       uint32_t id, const struct wl_interface *interface)
 {
@@ -159,9 +160,7 @@ wl_proxy_create_for_id(struct wl_proxy *factory,
 	proxy->queue = factory->queue;
 	proxy->id_deleted = 0;
 
-	pthread_mutex_lock(&display->mutex);
 	wl_map_insert_at(&display->objects, id, proxy);
-	pthread_mutex_unlock(&display->mutex);
 
 	return proxy;
 }
diff --git a/src/wayland-client.h b/src/wayland-client.h
index f0640102..cb1be9c7 100644
--- a/src/wayland-client.h
+++ b/src/wayland-client.h
@@ -39,9 +39,6 @@ void wl_event_queue_destroy(struct wl_event_queue *queue);
 void wl_proxy_marshal(struct wl_proxy *p, uint32_t opcode, ...);
 struct wl_proxy *wl_proxy_create(struct wl_proxy *factory,
 				 const struct wl_interface *interface);
-struct wl_proxy *wl_proxy_create_for_id(struct wl_proxy *factory,
-					uint32_t id,
-					const struct wl_interface *interface);
 
 void wl_proxy_destroy(struct wl_proxy *proxy);
 int wl_proxy_add_listener(struct wl_proxy *proxy,