diff --git a/src/views/Survey/views/Preview/js/logical.js b/src/views/Survey/views/Preview/js/logical.js
index c8cf555..e465e7f 100644
--- a/src/views/Survey/views/Preview/js/logical.js
+++ b/src/views/Survey/views/Preview/js/logical.js
@@ -145,7 +145,7 @@ function quesHandle(answer, logChild) {
       status = eval(`'${answer.value}'.${operatorHandle(logChild.operator)}('${logChild.value}')`);
     } else {
       // eslint-disable-next-line no-eval
-      status = eval(`${answer.value}${operatorHandle(logChild.operator)}${logChild.value}`);
+      status = eval(`'${answer.value}'${operatorHandle(logChild.operator)}'${logChild.value}'`);
     }
     return status;
   };