diff --git a/src/gallium/frontends/nine/buffer9.c b/src/gallium/frontends/nine/buffer9.c
index 0cdc6185d41..54f93c6c537 100644
--- a/src/gallium/frontends/nine/buffer9.c
+++ b/src/gallium/frontends/nine/buffer9.c
@@ -338,8 +338,15 @@ NineBuffer9_Lock( struct NineBuffer9 *This,
      * Our tests: On win 7 nvidia, D3DLOCK_DONOTWAIT does return
      * D3DERR_WASSTILLDRAWING if the resource is in use, except for DYNAMIC.
      * Our tests: some apps do use both DISCARD and NOOVERWRITE at the same
-     * time. On windows it seems to return different pointer, thus indicating
-     * DISCARD is taken into account. */
+     * time. On windows it seems to return different pointer in some conditions,
+     * creation flags and drivers. However these tests indicate having
+     * NOOVERWRITE win is a valid behaviour (NVidia).
+     */
+
+    /* Have NOOVERWRITE win over DISCARD. This is allowed (see above) and
+     * it prevents overconsuming buffers if apps do use both at the same time. */
+    if ((Flags & (D3DLOCK_DISCARD | D3DLOCK_NOOVERWRITE)) == (D3DLOCK_DISCARD | D3DLOCK_NOOVERWRITE))
+        Flags &= ~D3DLOCK_DISCARD;
 
     if (Flags & D3DLOCK_DISCARD)
         usage = PIPE_MAP_WRITE | PIPE_MAP_DISCARD_WHOLE_RESOURCE;