diff --git a/public/src/admin/manage/category.js b/public/src/admin/manage/category.js
index 9bbc9c47df..b6255fa251 100644
--- a/public/src/admin/manage/category.js
+++ b/public/src/admin/manage/category.js
@@ -109,11 +109,14 @@ define('admin/manage/category', [
 							callback: function () {
 								modal.find('.modal-footer button').prop('disabled', true);
 
-								const intervalId = setInterval(function () {
-									socket.emit('categories.getTopicCount', ajaxify.data.category.cid, function (err, count) {
-										if (err) {
-											return alerts.error(err);
-										}
+								const intervalId = setInterval(async () => {
+									if (!ajaxify.data.category) {
+										// Already navigated away
+										return;
+									}
+
+									try {
+										const { count } = await api.get(`/categories/${ajaxify.data.category.cid}/count`);
 
 										let percent = 0;
 										if (ajaxify.data.category.topic_count > 0) {
@@ -121,16 +124,21 @@ define('admin/manage/category', [
 										}
 
 										modal.find('.progress-bar').css({ width: percent + '%' });
-									});
+									} catch (err) {
+										clearInterval(intervalId);
+										alerts.error(err);
+									}
 								}, 1000);
 
 								api.del('/categories/' + ajaxify.data.category.cid).then(() => {
-									if (intervalId) {
-										clearInterval(intervalId);
-									}
-									modal.modal('hide');
-									alerts.success('[[admin/manage/categories:alert.purge-success]]');
-									ajaxify.go('admin/manage/categories');
+									setTimeout(() => {
+										if (intervalId) {
+											clearInterval(intervalId);
+										}
+										modal.modal('hide');
+										alerts.success('[[admin/manage/categories:alert.purge-success]]');
+										ajaxify.go('admin/manage/categories');
+									}, 5000);
 								}).catch(alerts.error);
 
 								return false;
diff --git a/public/src/client/category.js b/public/src/client/category.js
index a69ef64616..a89620cb34 100644
--- a/public/src/client/category.js
+++ b/public/src/client/category.js
@@ -9,7 +9,8 @@ define('forum/category', [
 	'categorySelector',
 	'hooks',
 	'alerts',
-], function (infinitescroll, share, navigator, topicList, sort, categorySelector, hooks, alerts) {
+	'api',
+], function (infinitescroll, share, navigator, topicList, sort, categorySelector, hooks, alerts, api) {
 	const Category = {};
 
 	$(window).on('action:ajaxify.start', function (ev, data) {
@@ -118,14 +119,9 @@ define('forum/category', [
 		navigator.scrollTop(0);
 	};
 
-	Category.toBottom = function () {
-		socket.emit('categories.getTopicCount', ajaxify.data.cid, function (err, count) {
-			if (err) {
-				return alerts.error(err);
-			}
-
-			navigator.scrollBottom(count - 1);
-		});
+	Category.toBottom = async () => {
+		const { count } = await api.get(`/categories/${ajaxify.data.category.cid}/count`);
+		navigator.scrollBottom(count - 1);
 	};
 
 	function loadTopicsAfter(after, direction, callback) {
diff --git a/public/src/sockets.js b/public/src/sockets.js
index 1a87e57646..e4ef8273e1 100644
--- a/public/src/sockets.js
+++ b/public/src/sockets.js
@@ -111,8 +111,8 @@ app = window.app || {};
 				alerts.alert(params);
 			});
 		});
-		socket.on('event:deprecated_call', function (data) {
-			console.warn('[socket.io] ', data.eventName, 'is now deprecated in favour of', data.replacement);
+		socket.on('event:deprecated_call', (data) => {
+			console.warn('[socket.io]', data.eventName, 'is now deprecated', data.replacement ? `in favour of ${data.replacement}` : 'with no alternative planned.');
 		});
 
 		socket.on('event:livereload', function () {
diff --git a/src/api/categories.js b/src/api/categories.js
index 47cb0ca8f6..28b2539a3a 100644
--- a/src/api/categories.js
+++ b/src/api/categories.js
@@ -77,6 +77,11 @@ categoriesAPI.delete = async function (caller, { cid }) {
 	});
 };
 
+categoriesAPI.getTopicCount = async (caller, { cid }) => {
+	const count = await categories.getCategoryField(cid, 'topic_count');
+	return { count };
+};
+
 categoriesAPI.getPosts = async (caller, { cid }) => await categories.getRecentReplies(cid, caller.uid, 0, 4);
 
 categoriesAPI.getPrivileges = async (caller, { cid }) => {
diff --git a/src/controllers/write/categories.js b/src/controllers/write/categories.js
index 52408a5400..8d4c0aebcf 100644
--- a/src/controllers/write/categories.js
+++ b/src/controllers/write/categories.js
@@ -35,6 +35,10 @@ Categories.delete = async (req, res) => {
 	helpers.formatApiResponse(200, res);
 };
 
+Categories.getTopicCount = async (req, res) => {
+	helpers.formatApiResponse(200, res, await api.categories.getTopicCount(req, { ...req.params }));
+};
+
 Categories.getPosts = async (req, res) => {
 	const posts = await api.categories.getPosts(req, { ...req.params });
 	helpers.formatApiResponse(200, res, posts);
diff --git a/src/routes/write/categories.js b/src/routes/write/categories.js
index 35957b440b..44a3020863 100644
--- a/src/routes/write/categories.js
+++ b/src/routes/write/categories.js
@@ -16,6 +16,7 @@ module.exports = function () {
 	setupApiRoute(router, 'put', '/:cid', [...middlewares], controllers.write.categories.update);
 	setupApiRoute(router, 'delete', '/:cid', [...middlewares], controllers.write.categories.delete);
 
+	setupApiRoute(router, 'get', '/:cid/count', [...middlewares], controllers.write.categories.getTopicCount);
 	setupApiRoute(router, 'get', '/:cid/posts', [...middlewares], controllers.write.categories.getPosts);
 
 	setupApiRoute(router, 'get', '/:cid/privileges', [...middlewares], controllers.write.categories.getPrivileges);
diff --git a/src/socket.io/categories.js b/src/socket.io/categories.js
index 8168176656..126bf5e7d6 100644
--- a/src/socket.io/categories.js
+++ b/src/socket.io/categories.js
@@ -24,6 +24,8 @@ SocketCategories.get = async function (socket) {
 };
 
 SocketCategories.getWatchedCategories = async function (socket) {
+	sockets.warnDeprecated(socket);
+
 	const [categoriesData, ignoredCids] = await Promise.all([
 		categories.getCategoriesByPrivilege('cid:0:children', socket.uid, 'find'),
 		user.getIgnoredCategories(socket.uid),
@@ -81,7 +83,9 @@ SocketCategories.loadMore = async function (socket, data) {
 };
 
 SocketCategories.getTopicCount = async function (socket, cid) {
-	return await categories.getCategoryField(cid, 'topic_count');
+	sockets.warnDeprecated(socket, 'GET /api/v3/categories/:cid');
+	const { count } = await api.categories.getTopicCount(socket, { cid });
+	return count;
 };
 
 SocketCategories.getCategoriesByPrivilege = async function (socket, privilege) {
diff --git a/src/socket.io/index.js b/src/socket.io/index.js
index 8f03eb2a9d..c10f271585 100644
--- a/src/socket.io/index.js
+++ b/src/socket.io/index.js
@@ -333,5 +333,9 @@ Sockets.warnDeprecated = (socket, replacement) => {
 			replacement: replacement,
 		});
 	}
-	winston.warn(`[deprecated]\n ${new Error('-').stack.split('\n').slice(2, 5).join('\n')}\n     use ${replacement}`);
+	winston.warn([
+		'[deprecated]',
+		`${new Error('-').stack.split('\n').slice(2, 5).join('\n')}`,
+		`      ${replacement ? `use ${replacement}` : 'there is no replacement for this call.'}`,
+	].join('\n'));
 };