diff --git a/src/app/qgsaddattrdialog.cpp b/src/app/qgsaddattrdialog.cpp
index 141e5fe0f4a..1cffd4da39b 100644
--- a/src/app/qgsaddattrdialog.cpp
+++ b/src/app/qgsaddattrdialog.cpp
@@ -128,6 +128,6 @@ QgsField QgsAddAttrDialog::field() const
            mLength->value(),
            mPrec->value(),
            mCommentEdit->text(),
-           ( QVariant::Type ) mTypeBox->currentData( Qt::UserRole ).toInt() == QVariant::Map ? QVariant::String : QVariant::Invalid
+           static_cast<QVariant::Type>( mTypeBox->currentData( Qt::UserRole ).toInt() ) == QVariant::Map ? QVariant::String : QVariant::Invalid
          );
 }
diff --git a/src/core/qgsfield.cpp b/src/core/qgsfield.cpp
index 14f8ceca42d..466d7ea3438 100644
--- a/src/core/qgsfield.cpp
+++ b/src/core/qgsfield.cpp
@@ -254,7 +254,7 @@ QString QgsField::displayString( const QVariant &v ) const
     if ( ok )
       return QLocale().toString( converted );
   }
-  else if ( d->typeName == QLatin1String( "json" ) || d->typeName == QLatin1String( "jsonb" ) || d->typeName == QLatin1String( "JSON" ) )
+  else if ( d->typeName.compare( QLatin1String( "json" ), Qt::CaseInsensitive ) == 0 || d->typeName == QLatin1String( "jsonb" ) )
   {
     QJsonDocument doc = QJsonDocument::fromVariant( v );
     return QString::fromUtf8( doc.toJson().data() );
diff --git a/src/gui/editorwidgets/qgslistwidgetfactory.cpp b/src/gui/editorwidgets/qgslistwidgetfactory.cpp
index e55538882be..49261d32a35 100644
--- a/src/gui/editorwidgets/qgslistwidgetfactory.cpp
+++ b/src/gui/editorwidgets/qgslistwidgetfactory.cpp
@@ -44,5 +44,5 @@ QgsEditorConfigWidget *QgsListWidgetFactory::configWidget( QgsVectorLayer *vl, i
 unsigned int QgsListWidgetFactory::fieldScore( const QgsVectorLayer *vl, int fieldIdx ) const
 {
   const QgsField field = vl->fields().field( fieldIdx );
-  return ( field.type() == QVariant::List || field.type() == QVariant::StringList || field.typeName() == QLatin1String( "json" ) || field.typeName() == QLatin1String( "jsonb" ) || field.typeName() == QLatin1String( "JSON" ) ) && field.subType() != QVariant::Invalid ? 20 : 0;
+  return ( field.type() == QVariant::List || field.type() == QVariant::StringList || field.typeName().compare( QLatin1String( "json" ), Qt::CaseInsensitive ) == 0 || field.typeName() == QLatin1String( "jsonb" ) ) && field.subType() != QVariant::Invalid ? 20 : 0;
 }
diff --git a/src/providers/ogr/qgsogrprovider.cpp b/src/providers/ogr/qgsogrprovider.cpp
index bca78366fc6..4f561b54e19 100644
--- a/src/providers/ogr/qgsogrprovider.cpp
+++ b/src/providers/ogr/qgsogrprovider.cpp
@@ -476,8 +476,10 @@ QgsOgrProvider::QgsOgrProvider( QString const &uri, const ProviderOptions &optio
       << QgsVectorDataProvider::NativeType( tr( "Whole number (integer)" ), QStringLiteral( "integer" ), QVariant::Int, 0, nMaxIntLen )
       << QgsVectorDataProvider::NativeType( tr( "Whole number (integer 64 bit)" ), QStringLiteral( "integer64" ), QVariant::LongLong, 0, nMaxInt64Len )
       << QgsVectorDataProvider::NativeType( tr( "Decimal number (real)" ), QStringLiteral( "double" ), QVariant::Double, 0, nMaxDoubleLen, 0, nMaxDoublePrec )
-      << QgsVectorDataProvider::NativeType( tr( "Text (string)" ), QStringLiteral( "string" ), QVariant::String, 0, 65535 )
-      << QgsVectorDataProvider::NativeType( tr( "Map (JSON)" ), QStringLiteral( "JSON" ), QVariant::Map, 0, 0, 0, 0, QVariant::String );
+      << QgsVectorDataProvider::NativeType( tr( "Text (string)" ), QStringLiteral( "string" ), QVariant::String, 0, 65535 );
+
+  if ( mGDALDriverName == QLatin1String( "GPKG" ) )
+    nativeTypes << QgsVectorDataProvider::NativeType( tr( "Map (JSON)" ), QStringLiteral( "JSON" ), QVariant::Map, 0, 0, 0, 0, QVariant::String );
 
   bool supportsDate = true;
   bool supportsTime = mGDALDriverName != QLatin1String( "ESRI Shapefile" ) && mGDALDriverName != QLatin1String( "GPKG" );
@@ -1053,7 +1055,6 @@ void QgsOgrProvider::loadFields()
         if ( OGR_Fld_GetSubType( fldDef ) == OFSTJSON )
         {
           ogrSubType = OFSTJSON;
-          QgsDebugMsg( QStringLiteral( "JSON Field found" ) );
           varType = QVariant::Map;
           varSubType = QVariant::String;
         }
@@ -1407,6 +1408,16 @@ OGRGeometryH QgsOgrProvider::ConvertGeometryIfNecessary( OGRGeometryH hGeom )
   return OGR_G_ForceTo( hGeom, layerGeomType, nullptr );
 }
 
+QString QgsOgrProvider::jsonStringValue( const QVariant &value )
+{
+  QString stringValue = QString::fromUtf8( QJsonDocument::fromVariant( value.toMap() ).toJson().data() );
+  if ( stringValue == QStringLiteral( "{\n}\n" ) )
+    stringValue = QString::fromUtf8( QJsonDocument::fromVariant( value.toList() ).toJson().data() );
+  if ( stringValue == QStringLiteral( "[\n]\n" ) && !value.toString().isEmpty() )
+    stringValue = value.toString();
+  return stringValue;
+}
+
 bool QgsOgrProvider::addFeaturePrivate( QgsFeature &f, Flags flags )
 {
   bool returnValue = true;
@@ -1536,13 +1547,7 @@ bool QgsOgrProvider::addFeaturePrivate( QgsFeature &f, Flags flags )
 
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,4,0)
           if ( OGR_Fld_GetSubType( fldDef ) == OFSTJSON )
-          {
-            stringValue = QString::fromUtf8( QJsonDocument::fromVariant( attrVal.toMap() ).toJson().data() );
-            if ( stringValue == QStringLiteral( "{\n}\n" ) )
-              stringValue = QString::fromUtf8( QJsonDocument::fromVariant( attrVal.toList() ).toJson().data() );
-            if ( stringValue == QStringLiteral( "[\n]\n" ) && !attrVal.toString().isEmpty() )
-              stringValue = attrVal.toString();
-          }
+            stringValue = jsonStringValue( attrVal );
           else
           {
             stringValue = attrVal.toString();
@@ -2131,17 +2136,9 @@ bool QgsOgrProvider::changeAttributeValues( const QgsChangedAttributesMap &attr_
             QString stringValue;
 #if GDAL_VERSION_NUM >= GDAL_COMPUTE_VERSION(2,4,0)
             if ( OGR_Fld_GetSubType( fd ) == OFSTJSON )
-            {
-              stringValue = QString::fromUtf8( QJsonDocument::fromVariant( it2->toMap() ).toJson().data() );
-              if ( stringValue == QStringLiteral( "{\n}\n" ) )
-                stringValue = QString::fromUtf8( QJsonDocument::fromVariant( it2->toList() ).toJson().data() );
-              if ( stringValue == QStringLiteral( "[\n]\n" ) && !it2->toString().isEmpty() )
-                stringValue = it2->toString();
-            }
+              stringValue = jsonStringValue( it2.value() );
             else
-            {
               stringValue = it2->toString();
-            }
 #else
             stringValue = it2->toString();
 #endif
diff --git a/src/providers/ogr/qgsogrprovider.h b/src/providers/ogr/qgsogrprovider.h
index 92b851727e7..a5c7f148dd1 100644
--- a/src/providers/ogr/qgsogrprovider.h
+++ b/src/providers/ogr/qgsogrprovider.h
@@ -284,6 +284,9 @@ class QgsOgrProvider : public QgsVectorDataProvider
 
     mutable QStringList mSubLayerList;
 
+    //! convert from json QVariant to QString
+    QString jsonStringValue( const QVariant &value );
+
     bool addFeaturePrivate( QgsFeature &f, QgsFeatureSink::Flags flags );
     //! Deletes one feature
     bool deleteFeature( QgsFeatureId id );