diff --git a/README.md b/README.md
index 0fe8dc4..dff9914 100644
--- a/README.md
+++ b/README.md
@@ -140,6 +140,7 @@ Register an event handler for the given type.
 ### off
 
 Remove an event handler for the given type.
+If omit the `handler`, all event handlers of the given type are deleted.
 
 #### Parameters
 
diff --git a/src/index.ts b/src/index.ts
index 5365b6e..4648156 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -24,7 +24,7 @@ export interface Emitter<Events extends Record<EventType, unknown>> {
 	on<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): void;
 	on(type: '*', handler: WildcardHandler<Events>): void;
 
-	off<Key extends keyof Events>(type: Key, handler: Handler<Events[Key]>): void;
+	off<Key extends keyof Events>(type: Key, handler?: Handler<Events[Key]>): void;
 	off(type: '*', handler: WildcardHandler<Events>): void;
 
 	emit<Key extends keyof Events>(type: Key, event: Events[Key]): void;
@@ -67,14 +67,20 @@ export default function mitt<Events extends Record<EventType, unknown>>(
 
 		/**
 		 * Remove an event handler for the given type.
+		 * If `handler` is omitted, all handlers of the given type are removed.
 		 * @param {string|symbol} type Type of event to unregister `handler` from, or `'*'`
-		 * @param {Function} handler Handler function to remove
+		 * @param {Function} [handler] Handler function to remove
 		 * @memberOf mitt
 		 */
-		off<Key extends keyof Events>(type: Key, handler: GenericEventHandler) {
+		off<Key extends keyof Events>(type: Key, handler?: GenericEventHandler) {
 			const handlers: Array<GenericEventHandler> | undefined = all!.get(type);
 			if (handlers) {
-				handlers.splice(handlers.indexOf(handler) >>> 0, 1);
+				if (handler) {
+					handlers.splice(handlers.indexOf(handler) >>> 0, 1);
+				}
+				else {
+					all.delete(type);
+				}
 			}
 		},