diff --git a/profanity-filter.js b/profanity-filter.js
index 7caf349..eaaa604 100644
--- a/profanity-filter.js
+++ b/profanity-filter.js
@@ -75,8 +75,8 @@ class ProfanityFilter {
         // Initialize custom words array
         this.customWords = [];
         
-        // Build initial patterns with base words only
-        this.patterns = this.buildPatterns();
+        // Initialize patterns to null; will be built during async initialization
+        this.patterns = null;
     }
     
     /**