diff --git a/clients/nitrogen/nitrogenconvertexceptions.cpp b/clients/nitrogen/nitrogenconvertexceptions.cpp
index 91637e741c..ded5ac6cde 100644
--- a/clients/nitrogen/nitrogenconvertexceptions.cpp
+++ b/clients/nitrogen/nitrogenconvertexceptions.cpp
@@ -105,7 +105,7 @@ int main( int argc, char *argv[] )
   QCoreApplication application( argc, argv );
   
   // generate filename
-  QString filename = KStandardDirs::locateLocal( "config", "nitrogen_xml_rc" );
+  const QString filename = KStandardDirs::locateLocal( "config", "nitrogen_xml_rc" );
   QTextStream( stdout ) << "nitrogen-convert-exceptions - reading file " << filename << endl;
   
   // open and get DomDocument
diff --git a/clients/nitrogen/nitrogenexception.cpp b/clients/nitrogen/nitrogenexception.cpp
index e0576c7a53..3531a25054 100644
--- a/clients/nitrogen/nitrogenexception.cpp
+++ b/clients/nitrogen/nitrogenexception.cpp
@@ -80,7 +80,7 @@ namespace Nitrogen
   }
   
   //_______________________________________________________
-  NitrogenException::Type NitrogenException::type( QString value )
+  NitrogenException::Type NitrogenException::type( const QString& value )
   {
     if( value == "Window Title" ) return WindowTitle;
     else if( value == "Window Class Name" ) return WindowClassName;
diff --git a/clients/nitrogen/nitrogenexception.h b/clients/nitrogen/nitrogenexception.h
index ad740dd095..e9e87a08bb 100644
--- a/clients/nitrogen/nitrogenexception.h
+++ b/clients/nitrogen/nitrogenexception.h
@@ -120,7 +120,7 @@ namespace Nitrogen
     //@{
     
     static QString typeName( Type );
-    static Type type( QString name );
+    static Type type( const QString& name );
 
     virtual QString typeName( void ) const
     { return typeName( type() ); }