diff --git a/types/chai-http/index.d.ts b/types/chai-http/index.d.ts
index 5b09d7fd28..f0957cc454 100644
--- a/types/chai-http/index.d.ts
+++ b/types/chai-http/index.d.ts
@@ -62,7 +62,7 @@ declare global {
 			end(callback?: (err: any, res: Response) => void): FinishedRequest;
 		}
 
-		interface FinishedRequest<T = Response>{
+		interface FinishedRequest<T = Response> {
 			then<TR1 = T, TR2 = void>(success?: (res: T) => TR1 | PromiseLike<TR1>, failure?: (err: any) => TR2 | PromiseLike<TR2>): FinishedRequest<TR1>;
 			catch(failure?: (err: any) => void): FinishedRequest<T>;
 		}
diff --git a/types/chai/index.d.ts b/types/chai/index.d.ts
index 01fc42631a..634956eaed 100644
--- a/types/chai/index.d.ts
+++ b/types/chai/index.d.ts
@@ -1338,6 +1338,18 @@ declare namespace Chai {
          */
         notFrozen<T>(object: T, message?: string): void;
 
+        /**
+         * Asserts that the target does not contain any values. For arrays and
+         * strings, it checks the length property. For Map and Set instances, it
+         * checks the size property. For non-function objects, it gets the count
+         * of own enumerable string keys.
+         *
+         * @type T   Type of object
+         * @param object   Actual value.
+         * @param message   Message to display on error.
+         */
+        isEmpty<T>(object: T, message?: string): void;
+
         /**
          * Asserts that the target contains values. For arrays and strings, it checks
          * the length property. For Map and Set instances, it checks the size property.