diff --git a/src/eventCategory.js b/src/eventCategory.js
index 3f72d03..29991f6 100644
--- a/src/eventCategory.js
+++ b/src/eventCategory.js
@@ -52,23 +52,6 @@ export default function eventCategory() {
 		return ensureEventHolderFor(name).unregister(binding);
 	};
 
-	/**
-	 * Like on() except callback will only be fired once
-	 *
-	 * @deprecated use registerOnce() instead
-	 * @param name
-	 * @param callback
-	 * @returns {*}
-	 */
-	that.onceOn = function (name, callback) {
-		// eslint-disable-next-line no-console
-		console.warn(
-			"Sending onceOn() to a category is deprecated. Send registerOnce() instead.",
-		);
-
-		return that.registerOnce(name, callback);
-	};
-
 	/**
 	 * Like on() except callback will only be fired once
 	 *
diff --git a/test/events.test.js b/test/events.test.js
index ca57db0..d2db94b 100644
--- a/test/events.test.js
+++ b/test/events.test.js
@@ -156,33 +156,3 @@ describe("events", () => {
 		expect(triggered).toBeTruthy();
 	});
 });
-
-describe("deprecated", () => {
-	/* eslint-disable no-console */
-	let originalConsoleWarn;
-
-	beforeEach(() => {
-		console.warn = jasmine.createSpy("console.warn");
-	});
-
-	beforeAll(() => {
-		originalConsoleWarn = console.warn;
-	});
-
-	afterAll(() => {
-		console.warn = originalConsoleWarn;
-	});
-
-	it("onceOn() category method delegates to registerOnce", () => {
-		// Arrange: an event
-		let someEvents = eventCategory();
-		let spy = jasmine.createSpy("registerOnce");
-
-		someEvents.registerOnce = spy;
-
-		someEvents.onceOn("namedEvent", "something else");
-
-		expect(spy).toHaveBeenCalledWith("namedEvent", "something else");
-		expect(console.warn).toHaveBeenCalled();
-	});
-});