diff --git a/umap/static/umap/vendors/markercluster/MarkerCluster.Default.css b/umap/static/umap/vendors/markercluster/MarkerCluster.Default.css
index a453b206..db8a1f2b 100755
--- a/umap/static/umap/vendors/markercluster/MarkerCluster.Default.css
+++ b/umap/static/umap/vendors/markercluster/MarkerCluster.Default.css
@@ -48,7 +48,7 @@
 .marker-cluster div {
 	width: 30px;
 	height: 30px;
-	margin-inline-start: 5px;
+	margin-left: 5px;
 	margin-top: 5px;
 
 	text-align: center;