diff --git a/glamor/glamor_render.c b/glamor/glamor_render.c
index f8d103d66..98343c3cf 100644
--- a/glamor/glamor_render.c
+++ b/glamor/glamor_render.c
@@ -731,7 +731,8 @@ glamor_setup_composite_vbo(ScreenPtr screen, int n_verts)
                                            glamor_priv->vbo_offset,
                                            vert_size,
                                            GL_MAP_WRITE_BIT |
-                                           GL_MAP_UNSYNCHRONIZED_BIT);
+                                           GL_MAP_UNSYNCHRONIZED_BIT |
+                                           GL_MAP_INVALIDATE_RANGE_BIT);
         assert(glamor_priv->vb != NULL);
         glamor_priv->vb -= glamor_priv->vbo_offset;
     }