diff --git a/app/assets/javascripts/discourse/controllers/composer.js.es6 b/app/assets/javascripts/discourse/controllers/composer.js.es6
index 1a6bf47dd0f..009fd35a8dd 100644
--- a/app/assets/javascripts/discourse/controllers/composer.js.es6
+++ b/app/assets/javascripts/discourse/controllers/composer.js.es6
@@ -297,6 +297,12 @@ export default Ember.Controller.extend({
   uploadIcon: () => uploadIcon(),
 
   actions: {
+    resetTagsSelection() {
+      if (this.get("model.tags")) {
+        this.set("model.tags", []);
+      }
+    },
+
     cancelUpload() {
       this.set("model.uploadCancelled", true);
     },
diff --git a/app/assets/javascripts/discourse/lib/plugin-api.js.es6 b/app/assets/javascripts/discourse/lib/plugin-api.js.es6
index 7f3b9e43898..e544c80ed94 100644
--- a/app/assets/javascripts/discourse/lib/plugin-api.js.es6
+++ b/app/assets/javascripts/discourse/lib/plugin-api.js.es6
@@ -38,7 +38,7 @@ import Sharing from "discourse/lib/sharing";
 import { addComposerUploadHandler } from "discourse/components/composer-editor";
 
 // If you add any methods to the API ensure you bump up this number
-const PLUGIN_API_VERSION = "0.8.24";
+const PLUGIN_API_VERSION = "0.8.25";
 
 class PluginApi {
   constructor(version, container) {
diff --git a/app/assets/javascripts/discourse/templates/composer.hbs b/app/assets/javascripts/discourse/templates/composer.hbs
index 94e8d44b643..7c75f0ba03a 100644
--- a/app/assets/javascripts/discourse/templates/composer.hbs
+++ b/app/assets/javascripts/discourse/templates/composer.hbs
@@ -60,7 +60,13 @@
 
                 {{#if model.showCategoryChooser}}
                   <div class="category-input">
-                    {{category-chooser fullWidthOnMobile=true value=model.categoryId scopedCategoryId=scopedCategoryId tabindex="3"}}
+                    {{category-chooser
+                      fullWidthOnMobile=true
+                      value=model.categoryId
+                      scopedCategoryId=scopedCategoryId
+                      onSelect=(action "resetTagsSelection")
+                      onSelectNone=(action "resetTagsSelection")
+                      tabindex="3"}}
                     {{popup-input-tip validation=categoryValidation}}
                   </div>
                 {{/if}}
diff --git a/app/assets/javascripts/select-kit/components/multi-select.js.es6 b/app/assets/javascripts/select-kit/components/multi-select.js.es6
index 86d8fcd22ae..b2a71ebf88c 100644
--- a/app/assets/javascripts/select-kit/components/multi-select.js.es6
+++ b/app/assets/javascripts/select-kit/components/multi-select.js.es6
@@ -2,7 +2,10 @@ import SelectKitComponent from "select-kit/components/select-kit";
 import computed from "ember-addons/ember-computed-decorators";
 import { on } from "ember-addons/ember-computed-decorators";
 const { get, isNone, isEmpty, makeArray, run } = Ember;
-import { applyOnSelectPluginApiCallbacks } from "select-kit/mixins/plugin-api";
+import {
+  applyOnSelectPluginApiCallbacks,
+  applyOnSelectNonePluginApiCallbacks
+} from "select-kit/mixins/plugin-api";
 
 export default SelectKitComponent.extend({
   pluginApiIdentifiers: ["multi-select"],
@@ -253,6 +256,11 @@ export default SelectKitComponent.extend({
       !computedContentItem ||
       computedContentItem.__sk_row_type === "noneRow"
     ) {
+      applyOnSelectNonePluginApiCallbacks(
+        this.get("pluginApiIdentifiers"),
+        this
+      );
+      this._boundaryActionHandler("onSelectNone");
       this.clearSelection();
       return;
     }
diff --git a/app/assets/javascripts/select-kit/components/single-select.js.es6 b/app/assets/javascripts/select-kit/components/single-select.js.es6
index 8be8102fce6..7713d51194b 100644
--- a/app/assets/javascripts/select-kit/components/single-select.js.es6
+++ b/app/assets/javascripts/select-kit/components/single-select.js.es6
@@ -5,7 +5,10 @@ import {
 } from "ember-addons/ember-computed-decorators";
 const { get, isNone, isEmpty, isPresent, run, makeArray } = Ember;
 
-import { applyOnSelectPluginApiCallbacks } from "select-kit/mixins/plugin-api";
+import {
+  applyOnSelectPluginApiCallbacks,
+  applyOnSelectNonePluginApiCallbacks
+} from "select-kit/mixins/plugin-api";
 
 export default SelectKitComponent.extend({
   pluginApiIdentifiers: ["single-select"],
@@ -211,6 +214,11 @@ export default SelectKitComponent.extend({
       !computedContentItem ||
       computedContentItem.__sk_row_type === "noneRow"
     ) {
+      applyOnSelectNonePluginApiCallbacks(
+        this.get("pluginApiIdentifiers"),
+        this
+      );
+      this._boundaryActionHandler("onSelectNone");
       this.clearSelection();
       return;
     }
diff --git a/app/assets/javascripts/select-kit/mixins/plugin-api.js.es6 b/app/assets/javascripts/select-kit/mixins/plugin-api.js.es6
index b34f88c51ae..daa1e362a7d 100644
--- a/app/assets/javascripts/select-kit/mixins/plugin-api.js.es6
+++ b/app/assets/javascripts/select-kit/mixins/plugin-api.js.es6
@@ -47,6 +47,15 @@ function modifyCollectionHeader(pluginApiIdentifiers, contentFunction) {
   _modifyCollectionHeaderCallbacks[pluginApiIdentifiers].push(contentFunction);
 }
 
+let _onSelectNoneCallbacks = {};
+function onSelectNone(pluginApiIdentifiers, mutationFunction) {
+  if (Ember.isNone(_onSelectNoneCallbacks[pluginApiIdentifiers])) {
+    _onSelectNoneCallbacks[pluginApiIdentifiers] = [];
+  }
+
+  _onSelectNoneCallbacks[pluginApiIdentifiers].push(mutationFunction);
+}
+
 let _onSelectCallbacks = {};
 function onSelect(pluginApiIdentifiers, mutationFunction) {
   if (Ember.isNone(_onSelectCallbacks[pluginApiIdentifiers])) {
@@ -102,6 +111,12 @@ export function applyOnSelectPluginApiCallbacks(identifiers, val, context) {
   });
 }
 
+export function applyOnSelectNonePluginApiCallbacks(identifiers, context) {
+  identifiers.forEach(key => {
+    (_onSelectNoneCallbacks[key] || []).forEach(c => c(context));
+  });
+}
+
 export function modifySelectKit(pluginApiIdentifiers) {
   return {
     appendContent: content => {
@@ -131,6 +146,10 @@ export function modifySelectKit(pluginApiIdentifiers) {
     onSelect: callback => {
       onSelect(pluginApiIdentifiers, callback);
       return modifySelectKit(pluginApiIdentifiers);
+    },
+    onSelectNone: callback => {
+      onSelectNone(pluginApiIdentifiers, callback);
+      return modifySelectKit(pluginApiIdentifiers);
     }
   };
 }
@@ -142,6 +161,7 @@ export function clearCallbacks() {
   _modifyHeaderComputedContentCallbacks = {};
   _modifyCollectionHeaderCallbacks = {};
   _onSelectCallbacks = {};
+  _onSelectNoneCallbacks = {};
 }
 
 const EMPTY_ARRAY = Object.freeze([]);
diff --git a/test/javascripts/acceptance/category-chooser-with-tags-test.js.es6 b/test/javascripts/acceptance/category-chooser-with-tags-test.js.es6
new file mode 100644
index 00000000000..234eb2d8565
--- /dev/null
+++ b/test/javascripts/acceptance/category-chooser-with-tags-test.js.es6
@@ -0,0 +1,39 @@
+import { acceptance } from "helpers/qunit-helpers";
+
+acceptance("CategoryChooser - with tags", {
+  loggedIn: true,
+  site: { can_tag_topics: true },
+  settings: {
+    tagging_enabled: true,
+    allow_uncategorized_topics: false
+  }
+});
+
+QUnit.test("resets tags when changing category", async assert => {
+  const categoryChooser = selectKit(".category-chooser");
+  const miniTagChooser = selectKit(".mini-tag-chooser");
+  const findSelected = () =>
+    find(".mini-tag-chooser .mini-tag-chooser-header .selected-name").text();
+
+  await visit("/");
+  await click("#create-topic");
+  await miniTagChooser.expand();
+  await miniTagChooser.selectRowByValue("monkey");
+
+  assert.equal(findSelected(), "monkey");
+
+  await categoryChooser.expand();
+  await categoryChooser.selectRowByValue(6);
+
+  assert.equal(findSelected(), "optional tags");
+
+  await miniTagChooser.expand();
+  await miniTagChooser.selectRowByValue("monkey");
+
+  assert.equal(findSelected(), "monkey");
+
+  await categoryChooser.expand();
+  await categoryChooser.selectNoneRow();
+
+  assert.equal(findSelected(), "optional tags");
+});
diff --git a/test/javascripts/components/single-select-test.js.es6 b/test/javascripts/components/single-select-test.js.es6
index 056c963400f..7e6c6158a40 100644
--- a/test/javascripts/components/single-select-test.js.es6
+++ b/test/javascripts/components/single-select-test.js.es6
@@ -501,6 +501,32 @@ componentTest("support modifying on select behavior through plugin api", {
   }
 });
 
+componentTest("support modifying on select none behavior through plugin api", {
+  template:
+    '<span class="on-select-none-test"></span>{{single-select none="none" content=content}}',
+
+  beforeEach() {
+    withPluginApi("0.8.25", api => {
+      api.modifySelectKit("select-kit").onSelectNone(() => {
+        find(".on-select-none-test").html("NONE");
+      });
+    });
+
+    this.set("content", [{ id: "1", name: "robin" }]);
+  },
+
+  async test(assert) {
+    await this.get("subject").expand();
+    await this.get("subject").selectRowByValue(1);
+    await this.get("subject").expand();
+    await this.get("subject").selectNoneRow();
+
+    assert.equal(find(".on-select-none-test").html(), "NONE");
+
+    clearCallbacks();
+  }
+});
+
 componentTest("with nameChanges", {
   template: "{{single-select content=content nameChanges=true}}",