diff --git a/src/gallium/auxiliary/util/u_vbuf.c b/src/gallium/auxiliary/util/u_vbuf.c
index 52b360ed7aa..0c9c349e00e 100644
--- a/src/gallium/auxiliary/util/u_vbuf.c
+++ b/src/gallium/auxiliary/util/u_vbuf.c
@@ -370,7 +370,7 @@ u_vbuf_translate_buffers(struct u_vbuf *mgr, struct translate_key *key,
 
       /* Subtract min_index so that indexing with the index buffer works. */
       if (unroll_indices) {
-         map -= vb->stride * min_index;
+         map -= (ptrdiff_t)vb->stride * min_index;
       }
 
       tr->set_buffer(tr, i, map, vb->stride, ~0);