diff --git a/src/Transformations/LoopCombining/loops_combiner.cpp b/src/Transformations/LoopCombining/loops_combiner.cpp
index ed08b6d..9ab3e2b 100644
--- a/src/Transformations/LoopCombining/loops_combiner.cpp
+++ b/src/Transformations/LoopCombining/loops_combiner.cpp
@@ -667,7 +667,7 @@ static void renameIterationVariables(LoopGraph* loop, const map<SgSymbol*, SgSym
 {
     if (loop)
     {
-        string& loopName = loop->loopSymbol();
+        const string& loopName = loop->loopSymbol();
         for (auto& [from, to] : symbols)
         {
             if (from->identifier() == loopName)