diff --git a/src/python_coupling/Shell.cpp b/src/python_coupling/Shell.cpp
index 183e329d3d6c13b748c61e52ccbb19e7ef359e25..5749511e067a1f848f6266667dbf2073bcfe1336 100644
--- a/src/python_coupling/Shell.cpp
+++ b/src/python_coupling/Shell.cpp
@@ -134,7 +134,7 @@ namespace python_coupling {
 
          if ( lineCounter == 1 && commandComplete )
             return true;
-         if ( strTrimmedLine.size() == 0 && isCompleteCommand(result) ) // multiline commands have to end with empty line
+         if ( strTrimmedLine.empty() && isCompleteCommand(result) ) // multiline commands have to end with empty line
             return true;
       }