diff --git a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
index 98044c91238..366290d214d 100644
--- a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
+++ b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.cpp
@@ -810,9 +810,9 @@ void decodeMsg(unsigned Val,
   StreamId = (Val & STREAM_ID_MASK_) >> STREAM_ID_SHIFT_;
 }
 
-int64_t encodeMsg(int64_t MsgId,
-                  int64_t OpId,
-                  int64_t StreamId) {
+uint64_t encodeMsg(uint64_t MsgId,
+                   uint64_t OpId,
+                   uint64_t StreamId) {
   return (MsgId << ID_SHIFT_) |
          (OpId << OP_SHIFT_) |
          (StreamId << STREAM_ID_SHIFT_);
diff --git a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
index be88ebe9972..6ffb4f02214 100644
--- a/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
+++ b/lib/Target/AMDGPU/Utils/AMDGPUBaseInfo.h
@@ -483,9 +483,9 @@ void decodeMsg(unsigned Val,
                uint16_t &StreamId);
 
 LLVM_READNONE
-int64_t encodeMsg(int64_t MsgId,
-                  int64_t OpId,
-                  int64_t StreamId);
+uint64_t encodeMsg(uint64_t MsgId,
+                   uint64_t OpId,
+                   uint64_t StreamId);
 
 } // namespace SendMsg