diff --git a/src/mem/ruby/protocol/GPU_VIPER-TCC.sm b/src/mem/ruby/protocol/GPU_VIPER-TCC.sm
index 9092222a4d..da4318bcf9 100644
--- a/src/mem/ruby/protocol/GPU_VIPER-TCC.sm
+++ b/src/mem/ruby/protocol/GPU_VIPER-TCC.sm
@@ -606,6 +606,7 @@ machine(MachineType:TCC, "TCC Cache")
           out_msg.Destination.add(in_msg.Requestor);
           out_msg.Sender := machineID;
           out_msg.MessageSize := MessageSizeType:Response_Data;
+          out_msg.instSeqNum := in_msg.instSeqNum;
           out_msg.DataBlk := cache_entry.DataBlk;
           out_msg.isGLCSet := in_msg.isGLCSet;
           out_msg.isSLCSet := in_msg.isSLCSet;