diff --git a/lib/cache.js b/lib/cache.js
index 255e1d06..5c7019eb 100644
--- a/lib/cache.js
+++ b/lib/cache.js
@@ -20,7 +20,7 @@ class MemoryCache {
       if (cached.expiresAt > Date.now() || cached.expiresAt === 0) {
         return cached.value;
       }
-      this.delete(key);
+      this.cache.delete(key);
     }
     return undefined;
   }
@@ -44,15 +44,6 @@ class MemoryCache {
     });
   }
 
-  /**
-   * Deletes cache entry for key
-   * @param {string} key Cache key
-   * @return {void}
-   */
-  delete (key) {
-    this.cache.delete(key);
-  }
-
   /**
    * Clear cache
    * @returns {void}