diff --git a/lizmap/modules/lizmap/classes/lizmapTiler.class.php b/lizmap/modules/lizmap/classes/lizmapTiler.class.php
index a1e750a3de..80fc534266 100644
--- a/lizmap/modules/lizmap/classes/lizmapTiler.class.php
+++ b/lizmap/modules/lizmap/classes/lizmapTiler.class.php
@@ -219,9 +219,7 @@ public static function getTileMatrixSetList($project, $wms_xml)
             $rootExtent[3] = $geoExtent[3];
         }
 
-        $scales = array_merge(array(), $project->getOption('mapScales'));
-        rsort($scales);
-
+        $scales = self::normalizeProjectScales($project);
         $projection = $project->getOption('projection');
 
         $tileMatrixSetList = array();
@@ -421,8 +419,7 @@ public static function getLayerTileInfo($layerName, $project, $wms_xml, $tileMat
             $rootExtent[3] = $geoExtent[3];
         }
 
-        $scales = array_merge(array(), $project->getOption('mapScales'));
-        rsort($scales);
+        $scales = self::normalizeProjectScales($project);
 
         $layers = $project->getLayers();
         $layer = $layers->{$layerName};
@@ -602,4 +599,15 @@ public static function getTileBbox($tileMatrixSet, $tileMatrixId, $tileRow, $til
 
         return (string) $minx.','.(string) $miny.','.(string) $maxx.','.(string) $maxy;
     }
+
+    private static function normalizeProjectScales($project)
+    {
+        $scales = array_merge(array(), $project->getOption('mapScales'));
+        if (reset($scales) == 0) {
+            $scales[0] = 1;
+        }
+        rsort($scales);
+
+        return $scales;
+    }
 }