diff --git a/modules/core/preferences.js b/modules/core/preferences.js
index e82d6e338..2a5a88378 100644
--- a/modules/core/preferences.js
+++ b/modules/core/preferences.js
@@ -20,7 +20,7 @@ const _listeners = {};
 //
 /**
  * @param {string} k
- * @param {string?} v
+ * @param {string?} [v]
  * @returns {boolean} true if the action succeeded
  */
 function corePreferences(k, v) {
diff --git a/modules/renderer/features.js b/modules/renderer/features.js
index 232e4a5ce..da12af03d 100644
--- a/modules/renderer/features.js
+++ b/modules/renderer/features.js
@@ -71,10 +71,17 @@ export function rendererFeatures(context) {
     }
 
 
+    /**
+     * @callback FilterFunction
+     * @param {Record<string, string>} tags
+     * @param {string} [geometry]
+     * @returns {boolean}
+     */
+
     /**
      * @param {string} k
-     * @param {(tags: Record<string, string>, geometry: string) => boolean} filter
-     * @param {?number} max
+     * @param {FilterFunction} filter
+     * @param {number} [max]
      */
     function defineRule(k, filter, max) {
         var isEnabled = true;
@@ -124,11 +131,11 @@ export function rendererFeatures(context) {
     }, 250);
 
     defineRule('building_parts', function isBuildingPart(tags) {
-        return tags['building:part'];
+        return !!tags['building:part'];
     });
 
     defineRule('indoor', function isIndoor(tags) {
-        return tags.indoor;
+        return !!tags.indoor;
     });
 
     defineRule('landuse', function isLanduse(tags, geometry) {
@@ -194,8 +201,8 @@ export function rendererFeatures(context) {
     });
 
     defineRule('aerialways', function isAerialways(tags) {
-        return tags.aerialway &&
-            tags.aerialway !== 'yes' &&
+        return !!tags?.aerialway && 
+            tags.aerialway !== 'yes' && 
             tags.aerialway !== 'station';
     });
 
@@ -260,7 +267,7 @@ export function rendererFeatures(context) {
         if (!arguments.length) {
             return _keys.filter(function(k) { return _rules[k].hidden(); });
         }
-        return _rules[k] && _rules[k].hidden();
+        return _rules[k]?.hidden();
     };