diff --git a/index.d.ts b/index.d.ts
index 5b93e3b..bdd3887 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -49,7 +49,10 @@ declare module '@fridgerator/pynode' {
    * let x = pynode.call('add', 1, 2)
    * x === 3 // true
    */
-  export function call(functionName: string, ...args: any[]): any;
+  export function call(functionName: string, ...args: any[], callback: (err: any, result: any) => void): void;
+  namespace call {
+    function __promisify__(functionName: string, ...args: any[]): Promise<any>;
+  }
 
   /**
    * Pass a string directly to the python interpreter.