diff --git a/types/murmurhash/index.d.ts b/types/murmurhash/index.d.ts
index 31c663fd33..eac6b500b7 100644
--- a/types/murmurhash/index.d.ts
+++ b/types/murmurhash/index.d.ts
@@ -9,21 +9,27 @@ export = murmurhash;
  * JS Implementation of MurmurHash3 (r136) (as of May 20, 2011)
  *
  * @param key - ASCII only
- * @param seed - Positive integer only
- * @return - 32-bit positive integer hash
+ * @param seed - (optional) positive integer
+ * @returns 32-bit positive integer hash
  */
-declare function murmurhash(key: string, seed: number): number;
+declare function murmurhash(key: string, seed?: number): number;
 
 declare namespace murmurhash {
-    // Circular reference from murmurhash
-    function v3(key: string, seed: number): number;
+    /**
+     * JS Implementation of MurmurHash3 (r136) (as of May 20, 2011)
+     *
+     * @param key - ASCII only
+     * @param seed - (optional) positive integer
+     * @returns 32-bit positive integer hash
+     */
+    function v3(key: string, seed?: number): number;
 
     /**
      * JS Implementation of MurmurHash2
      *
      * @param str - ASCII only
-     * @param seed - Positive integer only
-     * @return - 32-bit positive integer hash
+     * @param seed - (optional) positive integer
+     * @returns 32-bit positive integer hash
      */
-    function v2(str: string, seed: number): number;
+    function v2(str: string, seed?: number): number;
 }
diff --git a/types/murmurhash/murmurhash-tests.ts b/types/murmurhash/murmurhash-tests.ts
index ebbbf09cab..fe7fc9c501 100644
--- a/types/murmurhash/murmurhash-tests.ts
+++ b/types/murmurhash/murmurhash-tests.ts
@@ -3,6 +3,11 @@ import murmurhash = require('murmurhash');
 const stringValue = "test";
 let numberValue = 123;
 
+numberValue = murmurhash(stringValue);
 numberValue = murmurhash(stringValue, numberValue);
+
+numberValue = murmurhash.v2(stringValue);
 numberValue = murmurhash.v2(stringValue, numberValue);
+
+numberValue = murmurhash.v3(stringValue);
 numberValue = murmurhash.v3(stringValue, numberValue);