diff --git a/types/index.d.ts b/types/index.d.ts
index 0ebeac0933..9a60491443 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -623,7 +623,7 @@ declare module 'mongoose' {
 
     /** Adds static "class" methods to Models compiled from this schema. */
     static<K extends keyof TStaticMethods>(name: K, fn: TStaticMethods[K]): this;
-    static(obj: { [F in keyof TStaticMethods]: TStaticMethods[F] } & { [name: string]: (this: TModelType, ...args: any[]) => any }): this;
+    static(obj: { [F in keyof TStaticMethods]?: TStaticMethods[F] } & { [name: string]: (this: TModelType, ...args: any[]) => any }): this;
     static(name: string, fn: (this: TModelType, ...args: any[]) => any): this;
 
     /** Object of currently defined statics on this schema. */