diff --git a/src/amd/vulkan/radv_radeon_winsys.h b/src/amd/vulkan/radv_radeon_winsys.h
index dd644d22b64..0d4cd587eb8 100644
--- a/src/amd/vulkan/radv_radeon_winsys.h
+++ b/src/amd/vulkan/radv_radeon_winsys.h
@@ -103,8 +103,11 @@ enum radeon_value_id {
 };
 
 struct radeon_cmdbuf {
-   unsigned cdw;    /* Number of used dwords. */
-   unsigned max_dw; /* Maximum number of dwords. */
+   /* These are uint64_t to tell the compiler that buf can't alias them.
+    * If they're uint32_t the generated code needs to redundantly
+    * store and reload them between buf writes. */
+   uint64_t cdw;    /* Number of used dwords. */
+   uint64_t max_dw; /* Maximum number of dwords. */
    uint32_t *buf;   /* The base pointer of the chunk. */
 };