diff --git a/src/gallium/auxiliary/tgsi/tgsi_sanity.c b/src/gallium/auxiliary/tgsi/tgsi_sanity.c
index 36e27ea52f4..a14572597c5 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_sanity.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_sanity.c
@@ -216,6 +216,9 @@ iter_instruction(
          inst->FullDstRegisters[i].DstRegister.Index,
          "destination",
          FALSE );
+      if (!inst->FullDstRegisters[i].DstRegister.WriteMask) {
+         report_error(ctx, "Destination register has empty writemask");
+      }
    }
    for (i = 0; i < inst->Instruction.NumSrcRegs; i++) {
       check_register_usage(