diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 70b421d0411..87317555bd2 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -683,7 +683,7 @@ void MCAsmStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
       // emission domain.  This produces nicer output and silences potential
       // truncation warnings when round tripping through another assembler.
       uint64_t Shift = 64 - EmissionSize * 8;
-      assert(Shift < static_cast<unsigned>(
+      assert(Shift < static_cast<uint64_t>(
                          std::numeric_limits<unsigned long long>::digits) &&
              "undefined behavior");
       ValueToEmit &= ~0ULL >> Shift;