diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index aef83856..afeaf9eb 100644
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -87,6 +87,12 @@
 
   <!-- Shared memory support -->
   <interface name="wl_shm" version="1">
+    <enum name="error">
+      <entry name="invalid_visual" value="0"/>
+      <entry name="invalid_stride" value="1"/>
+      <entry name="invalid_fd" value="2"/>
+    </enum>
+
     <!-- Transfer a shm buffer to the server.  The allocated buffer
          would include at least stride * height bytes starting at the
          beginning of fd.  The file descriptor is transferred over the
diff --git a/wayland/wayland-shm.c b/wayland/wayland-shm.c
index 84441e29..8a15f4c1 100644
--- a/wayland/wayland-shm.c
+++ b/wayland/wayland-shm.c
@@ -117,24 +117,21 @@ shm_create_buffer(struct wl_client *client, struct wl_shm *shm,
 		  uint32_t stride, struct wl_visual *visual)
 {
 	struct wl_shm_buffer *buffer;
-	struct wl_display *display = wl_client_get_display(client);
-
 	void *data;
 
-	/* FIXME: Define a real exception event instead of abusing the
-	 * display.invalid_object error */
 	if (visual->object.interface != &wl_visual_interface) {
-		wl_client_post_error(client, (struct wl_object *) display,
-				     WL_DISPLAY_ERROR_INVALID_OBJECT,
-				     "invalid visual in create_buffer\n");
+		wl_client_post_error(client, &shm->object,
+				     WL_SHM_ERROR_INVALID_VISUAL,
+				     "invalid visual");
 		close(fd);
 		return;
 	}
 
 	if (width < 0 || height < 0 || stride < width) {
-		wl_client_post_error(client, (struct wl_object *) display,
-				     WL_DISPLAY_ERROR_INVALID_OBJECT,
-				     "invalid width, height or stride in create_buffer\n");
+		wl_client_post_error(client, &shm->object,
+				     WL_SHM_ERROR_INVALID_STRIDE,
+				     "invalid width, height or stride (%dx%d, %u)",
+				     width, height, stride);
 		close(fd);
 		return;
 	}
@@ -144,11 +141,9 @@ shm_create_buffer(struct wl_client *client, struct wl_shm *shm,
 
 	close(fd);
 	if (data == MAP_FAILED) {
-		/* FIXME: Define a real exception event instead of
-		 * abusing this one */
-		wl_client_post_error(client, (struct wl_object *) display,
-				     WL_DISPLAY_ERROR_INVALID_OBJECT,
-				     "failed to create image for fd %d\n");
+		wl_client_post_error(client, &shm->object,
+				     WL_SHM_ERROR_INVALID_FD,
+				     "failed mmap fd %d", fd);
 		return;
 	}