diff --git a/src/core/parseutil.cpp b/src/core/parseutil.cpp
index 5448229c..04cdbcc7 100644
--- a/src/core/parseutil.cpp
+++ b/src/core/parseutil.cpp
@@ -241,10 +241,11 @@ QList<Token> ParseUtil::generatePostfix(const QList<Token> &tokens) {
     }
 
     while (!operatorStack.isEmpty()) {
-        if (operatorStack.top().value == "(" || operatorStack.top().value == ")") {
+        Token token = operatorStack.pop();
+        if (token.value == "(" || token.value == ")") {
             recordError("Mismatched parentheses detected in expression!");
         } else {
-            output.append(operatorStack.pop());
+            output.append(token);
         }
     }