diff --git a/functor.cpp b/functor.cpp
index 253f0e9..e9d723b 100644
--- a/functor.cpp
+++ b/functor.cpp
@@ -63,7 +63,7 @@
         std::map<std::string, std::vector<std::string>> mapperResponse;
         mapperResponseMsg.read(mapperResponse);
 
-        if (mapperResponse.begin() == mapperResponse.end())
+        if (mapperResponse.empty())
         {
             return false;
         }