diff --git a/umap/static/umap/js/umap.core.js b/umap/static/umap/js/umap.core.js
index fbbbd901..a9398945 100644
--- a/umap/static/umap/js/umap.core.js
+++ b/umap/static/umap/js/umap.core.js
@@ -161,7 +161,7 @@ L.Util.detectFileType = (f) => {
 }
 
 L.Util.usableOption = (options, option) =>
-  options[option] !== undefined && options[option] !== '' && options[option] !== null
+  options[option] !== undefined && options[option] !== ''
 
 L.Util.greedyTemplate = (str, data, ignore) => {
   function getValue(data, path) {
diff --git a/umap/static/umap/test/_pre.js b/umap/static/umap/test/_pre.js
index fa3ad7fe..4c8d244f 100644
--- a/umap/static/umap/test/_pre.js
+++ b/umap/static/umap/test/_pre.js
@@ -92,14 +92,12 @@ var defaultDatalayerData = function (custom) {
     displayOnLoad: true,
     id: 62,
     pictogram_url: null,
-    opacity: null,
     weight: null,
     fillColor: '',
     color: '',
     stroke: true,
     smoothFactor: null,
     dashArray: '',
-    fillOpacity: null,
     fill: true,
   }
   return L.extend({}, _default, custom)