diff --git a/types/openlayers/openlayers-tests.ts b/types/openlayers/openlayers-tests.ts
index 6e28ad4cd2..d631a9e9bb 100644
--- a/types/openlayers/openlayers-tests.ts
+++ b/types/openlayers/openlayers-tests.ts
@@ -418,6 +418,14 @@ feature.setStyle(styleArray);
 feature.setStyle(featureStyleFunction);
 feature.setStyle(styleFunction);
 feature.setProperties(object);
+const nullStyleFunction = (feature: (ol.Feature|ol.render.Feature), resolution: number): null => {
+    return null;
+};
+const nullFeatureStyleFunction = (resolution: number): null => {
+  return null;
+};
+feature.setStyle(nullStyleFunction);
+feature.setStyle(nullFeatureStyleFunction);
 
 //
 // ol.View
@@ -573,6 +581,10 @@ const vectorLayer: ol.layer.Vector = new ol.layer.Vector({
     zIndex: -1
 });
 
+vectorLayer.setStyle(nullStyleFunction);
+vectorLayer.setStyle(null);
+vectorLayer.setStyle(undefined);
+
 //
 // ol.layer.VectorTile
 //