diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index b4f275d..b620fa4 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -66,7 +66,7 @@
 
 void
 MachineInstr::SetMachineOperand(unsigned int i,
-				unsigned int regNum, bool isdef=false)
+				int regNum, bool isdef=false)
 {
   assert(i < operands.size());
   operands[i].InitializeReg(regNum);