diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
index c4b1a72e114..c496ac923e4 100644
--- a/src/app/qgisapp.cpp
+++ b/src/app/qgisapp.cpp
@@ -4349,7 +4349,6 @@ void QgisApp::askUserForOGRSublayers( QgsVectorLayer *layer )
   }
 
   QStringList sublayers = layer->dataProvider()->subLayers();
-  QString layertype = layer->dataProvider()->storageType();
 
   QgsSublayersDialog::LayerDefinitionList list;
   Q_FOREACH ( const QString &sublayer, sublayers )
diff --git a/src/providers/db2/qgsdb2provider.cpp b/src/providers/db2/qgsdb2provider.cpp
index ae095bc78be..23d2ff588e9 100644
--- a/src/providers/db2/qgsdb2provider.cpp
+++ b/src/providers/db2/qgsdb2provider.cpp
@@ -1106,10 +1106,10 @@ bool QgsDb2Provider::addFeatures( QgsFeatureList &flist, Flags flags )
       query.bindValue( bindIdx,  bytea, QSql::In | QSql::Binary );
     }
 
-    QList<QVariant> list = query.boundValues().values();
-
 // Show bound values
 #if 0
+    QList<QVariant> list = query.boundValues().values();
+
     for ( int i = 0; i < list.size(); ++i )
     {
       QgsDebugMsg( QString( "i: %1; value: %2; type: %3" )
diff --git a/src/providers/grass/qgsgrassimport.cpp b/src/providers/grass/qgsgrassimport.cpp
index 5609805f5ea..95496ea2dc5 100644
--- a/src/providers/grass/qgsgrassimport.cpp
+++ b/src/providers/grass/qgsgrassimport.cpp
@@ -715,7 +715,9 @@ bool QgsGrassVectorImport::import()
   QgsDebugMsg( "waitForFinished" );
   mProcess->waitForFinished( 30000 );
 
+#ifdef QGISDEBUG
   QString stdoutString = mProcess->readAllStandardOutput().constData();
+#endif
   QString stderrString = mProcess->readAllStandardError().constData();
 
 #ifdef QGISDEBUG
diff --git a/src/providers/wfs/qgswfsdataitems.cpp b/src/providers/wfs/qgswfsdataitems.cpp
index c0e03f38a0f..2fba0ba6e54 100644
--- a/src/providers/wfs/qgswfsdataitems.cpp
+++ b/src/providers/wfs/qgswfsdataitems.cpp
@@ -89,8 +89,10 @@ void QgsWfsLayerItem::copyStyle()
 
   if ( !connection )
   {
+#ifdef QGISDEBUG
     QString errorMsg( QStringLiteral( "Cannot get style for layer %1" ).arg( this->name() ) );
     QgsDebugMsg( " Cannot get style: " + errorMsg );
+#endif
 #if 0
     // TODO: how to emit message from provider (which does not know about QgisApp)
     QgisApp::instance()->messageBar()->pushMessage( tr( "Cannot copy style" ),
@@ -105,8 +107,10 @@ void QgsWfsLayerItem::copyStyle()
   QgsGeoNodeStyle style = geoNodeRequest.fetchDefaultStyleBlocking( this->name() );
   if ( style.name.isEmpty() )
   {
+#ifdef QGISDEBUG
     QString errorMsg( QStringLiteral( "Cannot get style for layer %1" ).arg( this->name() ) );
     QgsDebugMsg( " Cannot get style: " + errorMsg );
+#endif
 #if 0
     // TODO: how to emit message from provider (which does not know about QgisApp)
     QgisApp::instance()->messageBar()->pushMessage( tr( "Cannot copy style" ),
diff --git a/src/providers/wms/qgsxyzconnection.cpp b/src/providers/wms/qgsxyzconnection.cpp
index 155c51e2b25..99c36c6d0ce 100644
--- a/src/providers/wms/qgsxyzconnection.cpp
+++ b/src/providers/wms/qgsxyzconnection.cpp
@@ -54,7 +54,6 @@ QStringList QgsXyzConnectionUtils::connectionList()
   {
     settings.beginGroup( "qgis/connections-xyz/" + s );
     bool isHidden = settings.value( QStringLiteral( "hidden" ), false ).toBool();
-    QString url = settings.value( QStringLiteral( "url" ), "" ).toString();
     settings.endGroup();
     if ( isHidden )
     {