diff --git a/lib/checkcondition.cpp b/lib/checkcondition.cpp
index 9b6834aef..1df4433a1 100644
--- a/lib/checkcondition.cpp
+++ b/lib/checkcondition.cpp
@@ -180,9 +180,9 @@ bool CheckCondition::assignIfParseScope(const Token * const assignTok,
                 }
                 if (Token::Match(tok2,"&&|%oror%|( %varid% ==|!= %num% &&|%oror%|)", varid)) {
                     const Token *vartok = tok2->next();
-                    const std::string& op(vartok->strAt(1));
                     const MathLib::bigint num2 = MathLib::toLongNumber(vartok->strAt(2));
                     if ((num & num2) != ((bitop=='&') ? num2 : num)) {
+                        const std::string& op(vartok->strAt(1));
                         const bool alwaysTrue = op == "!=";
                         const std::string condition(vartok->str() + op + vartok->strAt(2));
                         assignIfError(assignTok, tok2, condition, alwaysTrue);