diff --git a/contribs/gmf/src/services/querymanager.js b/contribs/gmf/src/services/querymanager.js
index 9624ede2b11..61403b57dd2 100644
--- a/contribs/gmf/src/services/querymanager.js
+++ b/contribs/gmf/src/services/querymanager.js
@@ -140,8 +140,9 @@ gmf.QueryManager.prototype.createSources_ = function(node) {
           }
         }, this);
         layers = childLayerNames.join(',');
-      } else if (node.type === 'WMS') {
-        validateLayerParams = true;
+        if (node.type === 'WMS' && childLayerNames.length == 1) {
+          validateLayerParams = true;
+        }
       }
 
       var source = {
diff --git a/src/services/query.js b/src/services/query.js
index db16f0d5ed5..f482205abc7 100644
--- a/src/services/query.js
+++ b/src/services/query.js
@@ -370,6 +370,8 @@ ngeo.Query.prototype.issueWMSGetFeatureInfoRequests_ = function(
         );
         var layerLayers = layerSource.getParams()['LAYERS'].split(',');
         var cfgLayer = item.source.wmsSource.getParams()['LAYERS'];
+        goog.asserts.assert(cfgLayer.indexOf(',') === -1,
+            'The LAYERS param contains more than one item');
         if (layerLayers.indexOf(cfgLayer) === -1) {
           continue;
         }