diff --git a/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp b/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
index 39145bca91e..a32734c2237 100644
--- a/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
+++ b/src/core/symbology-ng/qgsellipsesymbollayerv2.cpp
@@ -163,31 +163,31 @@ QgsSymbolLayerV2* QgsEllipseSymbolLayerV2::create( const QgsStringMap& propertie
   //compatibility with old project file format
   if ( !properties["width_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "width", new QgsDataDefined( new QgsExpression( properties["width_field"] ) ) );
+    layer->setDataDefinedProperty( "width", new QgsDataDefined( properties["width_field"] ) );
   }
   if ( !properties["height_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "height", new QgsDataDefined( new QgsExpression( properties["height_field"] ) ) );
+    layer->setDataDefinedProperty( "height", new QgsDataDefined( properties["height_field"] ) );
   }
   if ( !properties["rotation_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "rotation", new QgsDataDefined( new QgsExpression( properties["rotation_field"] ) ) );
+    layer->setDataDefinedProperty( "rotation", new QgsDataDefined( properties["rotation_field"] ) );
   }
   if ( !properties["outline_width_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "outline_width", new QgsDataDefined( new QgsExpression( properties[ "outline_width_field" ] ) ) );
+    layer->setDataDefinedProperty( "outline_width", new QgsDataDefined( properties[ "outline_width_field" ] ) );
   }
   if ( !properties["fill_color_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "fill_color", new QgsDataDefined( new QgsExpression( properties["fill_color_field"] ) ) );
+    layer->setDataDefinedProperty( "fill_color", new QgsDataDefined( properties["fill_color_field"] ) );
   }
   if ( !properties["outline_color_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "outline_color", new QgsDataDefined( new QgsExpression( properties["outline_color_field"] ) ) );
+    layer->setDataDefinedProperty( "outline_color", new QgsDataDefined( properties["outline_color_field"] ) );
   }
   if ( !properties["symbol_name_field"].isEmpty() )
   {
-    layer->setDataDefinedProperty( "symbol_name", new QgsDataDefined( new QgsExpression( properties["symbol_name_field"] ) ) );
+    layer->setDataDefinedProperty( "symbol_name", new QgsDataDefined( properties["symbol_name_field"] ) );
   }
 
   return layer;
diff --git a/src/core/symbology-ng/qgsrulebasedrendererv2.cpp b/src/core/symbology-ng/qgsrulebasedrendererv2.cpp
index 10c812aa19e..80b5bf14947 100644
--- a/src/core/symbology-ng/qgsrulebasedrendererv2.cpp
+++ b/src/core/symbology-ng/qgsrulebasedrendererv2.cpp
@@ -1220,7 +1220,7 @@ void QgsRuleBasedRendererV2::convertToDataDefinedSymbology( QgsSymbolV2* symbol,
         if ( ! sizeScaleField.isNull() )
         {
           sizeExpression = QString( "%1*(%2)" ).arg( msl->size() ).arg( sizeScaleField );
-          msl->setDataDefinedProperty( "size", new QgsDataDefined( new QgsExpression( sizeExpression ) ) );
+          msl->setDataDefinedProperty( "size", new QgsDataDefined( sizeExpression ) );
         }
         if ( ! rotationField.isNull() )
         {
@@ -1237,7 +1237,7 @@ void QgsRuleBasedRendererV2::convertToDataDefinedSymbology( QgsSymbolV2* symbol,
           {
             QgsLineSymbolLayerV2* lsl = static_cast<QgsLineSymbolLayerV2*>( symbol->symbolLayer( j ) );
             sizeExpression = QString( "%1*(%2)" ).arg( lsl->width() ).arg( sizeScaleField );
-            lsl->setDataDefinedProperty( "width", new QgsDataDefined( new QgsExpression( sizeExpression ) ) );
+            lsl->setDataDefinedProperty( "width", new QgsDataDefined( sizeExpression ) );
           }
           if ( symbol->symbolLayer( j )->layerType() == "MarkerLine" )
           {
@@ -1246,7 +1246,7 @@ void QgsRuleBasedRendererV2::convertToDataDefinedSymbology( QgsSymbolV2* symbol,
             {
               QgsMarkerSymbolLayerV2* msl = static_cast<QgsMarkerSymbolLayerV2*>( marker->symbolLayer( k ) );
               sizeExpression = QString( "%1*(%2)" ).arg( msl->size() ).arg( sizeScaleField );
-              msl->setDataDefinedProperty( "size", new QgsDataDefined( new QgsExpression( sizeExpression ) ) );
+              msl->setDataDefinedProperty( "size", new QgsDataDefined( sizeExpression ) );
             }
           }
         }