diff --git a/tests/d3d12.c b/tests/d3d12.c
index e2c538e4f..5aaef4229 100644
--- a/tests/d3d12.c
+++ b/tests/d3d12.c
@@ -32539,6 +32539,7 @@ static void test_resource_allocation_info(void)
         return;
     }
 
+    memset(&desc, 0xcc, sizeof(desc));
     info = ID3D12Device_GetResourceAllocationInfo(device, 0, 0, &desc);
     ok(info.SizeInBytes == 0, "Got unexpected size %"PRIu64".\n", info.SizeInBytes);
     /* Alignment on AMD Windows is 1, but this doesn't seem important to check. */