diff --git a/app/javascript/flavours/glitch/actions/notifications.js b/app/javascript/flavours/glitch/actions/notifications.js
index ee148e4ef2f..fb84cd01e5f 100644
--- a/app/javascript/flavours/glitch/actions/notifications.js
+++ b/app/javascript/flavours/glitch/actions/notifications.js
@@ -28,6 +28,8 @@ export const NOTIFICATIONS_SCROLL_TOP = 'NOTIFICATIONS_SCROLL_TOP';
 export const NOTIFICATIONS_MOUNT   = 'NOTIFICATIONS_MOUNT';
 export const NOTIFICATIONS_UNMOUNT = 'NOTIFICATIONS_UNMOUNT';
 
+export const NOTIFICATIONS_SET_VISIBILITY = 'NOTIFICATIONS_SET_VISIBILITY';
+
 defineMessages({
   mention: { id: 'notification.mention', defaultMessage: '{name} mentioned you' },
 });
@@ -231,3 +233,10 @@ export function unmountNotifications() {
     type: NOTIFICATIONS_UNMOUNT,
   };
 };
+
+export function notificationsSetVisibility(visibility) {
+  return {
+    type: NOTIFICATIONS_SET_VISIBILITY,
+    visibility: visibility,
+  };
+};
diff --git a/app/javascript/flavours/glitch/features/ui/index.js b/app/javascript/flavours/glitch/features/ui/index.js
index 1cff94321e8..c41436090ca 100644
--- a/app/javascript/flavours/glitch/features/ui/index.js
+++ b/app/javascript/flavours/glitch/features/ui/index.js
@@ -10,7 +10,7 @@ import { isMobile } from 'flavours/glitch/util/is_mobile';
 import { debounce } from 'lodash';
 import { uploadCompose, resetCompose } from 'flavours/glitch/actions/compose';
 import { expandHomeTimeline } from 'flavours/glitch/actions/timelines';
-import { expandNotifications } from 'flavours/glitch/actions/notifications';
+import { expandNotifications, notificationsSetVisibility } from 'flavours/glitch/actions/notifications';
 import { fetchFilters } from 'flavours/glitch/actions/filters';
 import { clearHeight } from 'flavours/glitch/actions/height_cache';
 import { WrappedSwitch, WrappedRoute } from 'flavours/glitch/util/react_router_helpers';
@@ -206,7 +206,27 @@ export default class UI extends React.Component {
     }
   }
 
+  handleVisibilityChange = () => {
+    const visibility = !document[this.visibilityHiddenProp];
+    this.props.dispatch(notificationsSetVisibility(visibility));
+  }
+
   componentWillMount () {
+    if (typeof document.hidden !== 'undefined') { // Opera 12.10 and Firefox 18 and later support
+      this.visibilityHiddenProp = 'hidden';
+      this.visibilityChange = 'visibilitychange';
+    } else if (typeof document.msHidden !== 'undefined') {
+      this.visibilityHiddenProp = 'msHidden';
+      this.visibilityChange = 'msvisibilitychange';
+    } else if (typeof document.webkitHidden !== 'undefined') {
+      this.visibilityHiddenProp = 'webkitHidden';
+      this.visibilityChange = 'webkitvisibilitychange';
+    }
+    if (this.visibilityChange !== undefined) {
+      document.addEventListener(this.visibilityChange, this.handleVisibilityChange, false);
+      this.handleVisibilityChange();
+    }
+
     window.addEventListener('beforeunload', this.handleBeforeUnload, false);
     window.addEventListener('resize', this.handleResize, { passive: true });
     document.addEventListener('dragenter', this.handleDragEnter, false);
@@ -250,6 +270,10 @@ export default class UI extends React.Component {
   }
 
   componentWillUnmount () {
+    if (this.visibilityChange !== undefined) {
+      document.removeEventListener(this.visibilityChange, this.handleVisibilityChange);
+    }
+
     window.removeEventListener('beforeunload', this.handleBeforeUnload);
     window.removeEventListener('resize', this.handleResize);
     document.removeEventListener('dragenter', this.handleDragEnter);
diff --git a/app/javascript/flavours/glitch/reducers/notifications.js b/app/javascript/flavours/glitch/reducers/notifications.js
index 9087e226ca7..0b816e85eec 100644
--- a/app/javascript/flavours/glitch/reducers/notifications.js
+++ b/app/javascript/flavours/glitch/reducers/notifications.js
@@ -1,6 +1,7 @@
 import {
   NOTIFICATIONS_MOUNT,
   NOTIFICATIONS_UNMOUNT,
+  NOTIFICATIONS_SET_VISIBILITY,
   NOTIFICATIONS_UPDATE,
   NOTIFICATIONS_EXPAND_SUCCESS,
   NOTIFICATIONS_EXPAND_REQUEST,
@@ -31,6 +32,7 @@ const initialState = ImmutableMap({
   lastReadId: '0',
   isLoading: false,
   cleaningMode: false,
+  isTabVisible: true,
   // notification removal mark of new notifs loaded whilst cleaningMode is true.
   markNewForDelete: false,
 });
@@ -44,7 +46,7 @@ const notificationToMap = (state, notification) => ImmutableMap({
 });
 
 const normalizeNotification = (state, notification) => {
-  const top = state.get('top') && state.get('mounted') > 0;
+  const top = !shouldCountUnreadNotifications(state);
 
   if (top) {
     state = state.set('lastReadId', notification.id);
@@ -62,7 +64,7 @@ const normalizeNotification = (state, notification) => {
 };
 
 const expandNormalizedNotifications = (state, notifications, next) => {
-  const top = state.get('top') && state.get('mounted') > 0;
+  const top = !(shouldCountUnreadNotifications(state));
   const lastReadId = state.get('lastReadId');
   let items = ImmutableList();
 
@@ -112,7 +114,9 @@ const clearUnread = (state) => {
 }
 
 const updateTop = (state, top) => {
-  if (top && state.get('mounted') > 0) {
+  state = state.set('top', top);
+
+  if (!shouldCountUnreadNotifications(state)) {
     state = clearUnread(state);
   }
 
@@ -120,7 +124,7 @@ const updateTop = (state, top) => {
 };
 
 const deleteByStatus = (state, statusId) => {
-  const top = state.get('top') && state.get('mounted') > 0;
+  const top = !(shouldCountUnreadNotifications(state));
   if (!top) {
     const lastReadId = state.get('lastReadId');
     const deletedUnread = state.get('items').filter(item => item !== null && item.get('status') === statusId && compareId(item.get('id'), lastReadId) > 0);
@@ -157,14 +161,36 @@ const deleteMarkedNotifs = (state) => {
   return state.update('items', list => list.filterNot(item => item.get('markedForDelete')));
 };
 
+const updateMounted = (state) => {
+  state = state.update('mounted', count => count + 1);
+  if (!shouldCountUnreadNotifications(state)) {
+    state = clearUnread(state);
+  }
+  return state;
+};
+
+const updateVisibility = (state, visibility) => {
+  state = state.set('isTabVisible', visibility);
+  if (!shouldCountUnreadNotifications(state)) {
+    state = clearUnread(state);
+  }
+  return state;
+};
+
+const shouldCountUnreadNotifications = (state) => {
+  return !(state.get('isTabVisible') && state.get('top') && state.get('mounted') > 0);
+};
+
 export default function notifications(state = initialState, action) {
   let st;
 
   switch(action.type) {
   case NOTIFICATIONS_MOUNT:
-    return (state.get('top') ? clearUnread(state) : state).update('mounted', count => count + 1);
+    return updateMounted(state);
   case NOTIFICATIONS_UNMOUNT:
     return state.update('mounted', count => count - 1);
+  case NOTIFICATIONS_SET_VISIBILITY:
+    return updateVisibility(state, action.visibility);
   case NOTIFICATIONS_EXPAND_REQUEST:
   case NOTIFICATIONS_DELETE_MARKED_REQUEST:
     return state.set('isLoading', true);