diff --git a/llvm/utils/TableGen/CodeGenInstruction.h b/llvm/utils/TableGen/CodeGenInstruction.h
index 11a3acd8e72335..963c9f0b259259 100644
--- a/llvm/utils/TableGen/CodeGenInstruction.h
+++ b/llvm/utils/TableGen/CodeGenInstruction.h
@@ -301,7 +301,7 @@ class CodeGenInstruction {
   Record *InferredFrom;
 
   // The enum value assigned by CodeGenTarget::computeInstrsByEnum.
-  mutable unsigned EnumVal;
+  mutable unsigned EnumVal = 0;
 
   CodeGenInstruction(Record *R);