diff --git a/node-git/node-git.d.ts b/node-git/node-git.d.ts
index dadfc8ba8b..7e29b0ffd5 100644
--- a/node-git/node-git.d.ts
+++ b/node-git/node-git.d.ts
@@ -17,7 +17,7 @@ declare module "git" {
 
         git(functionName:any, options:any, ...args:any[]):void; // last element is callback
 
-        call_git(prefix:string, command:any, postfix:string, options:any, args:any, callback:Function):void;
+        call_git(prefix:string, command:any, postfix:string, options:any, args:any, callback: (error: any, result: string) => void):void;
 
         rev_list(callback:Function):void;