diff --git a/src/providers/wfs/qgsbackgroundcachedshareddata.cpp b/src/providers/wfs/qgsbackgroundcachedshareddata.cpp
index c04098821aa..9f9c7b53dc3 100644
--- a/src/providers/wfs/qgsbackgroundcachedshareddata.cpp
+++ b/src/providers/wfs/qgsbackgroundcachedshareddata.cpp
@@ -588,7 +588,7 @@ void QgsBackgroundCachedSharedData::serializeFeatures( QVector<QgsFeatureUniqueI
     }
     else
     {
-      cachedFeature.setAttribute( hexwkbGeomIdx, QVariant( QString() ) );
+      cachedFeature.setAttribute( hexwkbGeomIdx, QVariant() );
     }
 
     const QString &uniqueId = featPair.second;