diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp
index 3d4f2ab30f5..a7c6104aaa2 100644
--- a/utils/TableGen/AsmWriterEmitter.cpp
+++ b/utils/TableGen/AsmWriterEmitter.cpp
@@ -737,7 +737,7 @@ namespace {
 
 struct AliasPriorityComparator {
   typedef std::pair<CodeGenInstAlias, int> ValueType;
-  bool operator()(const ValueType &LHS, const ValueType &RHS) {
+  bool operator()(const ValueType &LHS, const ValueType &RHS) const {
     if (LHS.second ==  RHS.second) {
       // We don't actually care about the order, but for consistency it
       // shouldn't depend on pointer comparisons.