diff --git a/src/providers/wms/qgswmsprovider.cpp b/src/providers/wms/qgswmsprovider.cpp
index 407ef083ffee2..0f62d54eb3897 100644
--- a/src/providers/wms/qgswmsprovider.cpp
+++ b/src/providers/wms/qgswmsprovider.cpp
@@ -600,11 +600,12 @@ bool QgsWmsProvider::setImageCrs( QString const &crs )
 
 void QgsWmsProvider::setQueryItem( QUrlQuery &url, const QString &item, const QString &value )
 {
-  url.removeQueryItem( item );
+  QString key = QUrl::toPercentEncoding( item );
+  url.removeQueryItem( key );
   if ( value.isNull() )
-    url.addQueryItem( item, "" );
+    url.addQueryItem( key, "" );
   else
-    url.addQueryItem( item, value );
+    url.addQueryItem( key, QUrl::toPercentEncoding( value ) );
 }
 
 void QgsWmsProvider::setFormatQueryItem( QUrlQuery &url )
@@ -1261,8 +1262,8 @@ QUrl QgsWmsProvider::createRequestUrlWMS( const QgsRectangle &viewExtent, int pi
   {
     if ( mActiveSubLayerVisibility.constFind( *it ).value() )
     {
-      visibleLayers += QUrl::toPercentEncoding( *it );
-      visibleStyles += QUrl::toPercentEncoding( *it2 );
+      visibleLayers += *it;
+      visibleStyles += *it2;
     }
 
     ++it2;
diff --git a/tests/src/providers/testqgswmsprovider.cpp b/tests/src/providers/testqgswmsprovider.cpp
index b57055c72f8f3..07ba75ead97b3 100644
--- a/tests/src/providers/testqgswmsprovider.cpp
+++ b/tests/src/providers/testqgswmsprovider.cpp
@@ -100,7 +100,7 @@ class TestQgsWmsProvider: public QgsTest
       QgsWmsProvider provider( failingAddress, QgsDataProvider::ProviderOptions(), mCapabilities );
       QUrl url( provider.createRequestUrlWMS( QgsRectangle( 0, 0, 90, 90 ), 100, 100 ) );
       QCOMPARE( url.toString(), QString( "http://localhost:8380/mapserv?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap"
-                                         "&BBOX=0,0,90,90&CRS=CRS:84&WIDTH=100&HEIGHT=100&LAYERS=&"
+                                         "&BBOX=0%2C0%2C90%2C90&CRS=CRS%3A84&WIDTH=100&HEIGHT=100&LAYERS=&"
                                          "STYLES=&FORMAT=&TRANSPARENT=TRUE" ) );
     }
 
@@ -116,8 +116,8 @@ class TestQgsWmsProvider: public QgsTest
       QVERIFY( cap.parseResponse( content, config ) );
       QgsWmsProvider provider( failingAddress, QgsDataProvider::ProviderOptions(), &cap );
       QUrl url( provider.createRequestUrlWMS( QgsRectangle( 0, 0, 90, 90 ), 100, 100 ) );
-      QCOMPARE( url.toString(), QString( "http://localhost:8380/mapserv?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=0,0,90,90&"
-                                         "CRS=EPSG:2056&WIDTH=100&HEIGHT=100&"
+      QCOMPARE( url.toString(), QString( "http://localhost:8380/mapserv?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=0%2C0%2C90%2C90&"
+                                         "CRS=EPSG%3A2056&WIDTH=100&HEIGHT=100&"
                                          "LAYERS=plus%2Bsign&STYLES=&FORMAT=&TRANSPARENT=TRUE" ) );
     }