diff --git a/nouveau/private.h b/nouveau/private.h
index dcc23d16..b81d4b1e 100644
--- a/nouveau/private.h
+++ b/nouveau/private.h
@@ -13,6 +13,7 @@
 
 /*
  * 0x00000001 dump all pushbuffers
+ * 0x00000002 submit pushbuffers synchronously
  * 0x80000000 if compiled with SIMULATE return -EINVAL for all pb submissions
  */
 drm_private extern uint32_t nouveau_debug;
diff --git a/nouveau/pushbuf.c b/nouveau/pushbuf.c
index 7f1ed8ca..10ff3f57 100644
--- a/nouveau/pushbuf.c
+++ b/nouveau/pushbuf.c
@@ -339,6 +339,8 @@ pushbuf_submit(struct nouveau_pushbuf *push, struct nouveau_object *chan)
 		req.suffix0 = nvpb->suffix0;
 		req.suffix1 = nvpb->suffix1;
 		req.vram_available = 0; /* for valgrind */
+		if (dbg_on(1))
+			req.vram_available |= NOUVEAU_GEM_PUSHBUF_SYNC;
 		req.gart_available = 0;
 
 		if (dbg_on(0))