diff --git a/types/mongoose/index.d.ts b/types/mongoose/index.d.ts
index a94f3a691d..ba0e6344cb 100644
--- a/types/mongoose/index.d.ts
+++ b/types/mongoose/index.d.ts
@@ -2274,6 +2274,12 @@ declare module "mongoose" {
     /** Adds a collation. */
     collation(options: CollationOptions): this;
 
+    /**
+     * Appends a new $count operator to this aggregate pipeline.
+     * @param countName name of the count field
+     */
+    count(countName: string): this;
+
     /**
      * Sets the cursor option option for the aggregation query (ignored for < 2.6.0).
      * Note the different syntax below: .exec() returns a cursor object, and no callback