diff --git a/app/soapbox/reducers/__tests__/auth-test.js b/app/soapbox/reducers/__tests__/auth-test.js
index a149042c4..77a9b1965 100644
--- a/app/soapbox/reducers/__tests__/auth-test.js
+++ b/app/soapbox/reducers/__tests__/auth-test.js
@@ -8,6 +8,7 @@ import {
   VERIFY_CREDENTIALS_FAIL,
   SWITCH_ACCOUNT,
 } from 'soapbox/actions/auth';
+import { ME_FETCH_SKIP } from 'soapbox/actions/me';
 
 describe('auth reducer', () => {
   it('should return the initial state', () => {
@@ -250,4 +251,13 @@ describe('auth reducer', () => {
       expect(result.get('me')).toEqual('5678');
     });
   });
+
+  describe('ME_FETCH_SKIP', () => {
+    it('sets `me` to null', () => {
+      const state = fromJS({ me: '1234' });
+      const action = { type: ME_FETCH_SKIP };
+      const result = reducer(state, action);
+      expect(result.get('me')).toEqual(null);
+    });
+  });
 });
diff --git a/app/soapbox/reducers/auth.js b/app/soapbox/reducers/auth.js
index 5985939da..29bc8fcd8 100644
--- a/app/soapbox/reducers/auth.js
+++ b/app/soapbox/reducers/auth.js
@@ -7,7 +7,8 @@ import {
   VERIFY_CREDENTIALS_SUCCESS,
   VERIFY_CREDENTIALS_FAIL,
 } from '../actions/auth';
-import { Map as ImmutableMap, fromJS } from 'immutable';
+import { ME_FETCH_SKIP } from '../actions/me';
+import { Map as ImmutableMap, List as ImmutableList, fromJS } from 'immutable';
 
 const defaultState = ImmutableMap({
   app: ImmutableMap(),
@@ -16,31 +17,50 @@ const defaultState = ImmutableMap({
   me: null,
 });
 
+const validId = id => typeof id === 'string' && id !== 'null' && id !== 'undefined';
+
 const getSessionUser = () => {
   const id = sessionStorage.getItem('soapbox:auth:me');
-  if (id && typeof id === 'string' && id !== 'null' && id !== 'undefined') {
-    return id;
-  } else {
-    return undefined;
-  }
+  return validId(id) ? id : undefined;
 };
 
 const sessionUser = getSessionUser();
 const localState = fromJS(JSON.parse(localStorage.getItem('soapbox:auth')));
 
+// Checks if the user has an ID and access token
+const validUser = user => {
+  try {
+    return validId(user.get('id')) && validId(user.get('access_token'));
+  } catch(e) {
+    return false;
+  }
+};
+
+// Finds the first valid user in the state
+const firstValidUser = state => state.get('users', ImmutableMap()).find(validUser);
+
 // If `me` doesn't match an existing user, attempt to shift it.
 const maybeShiftMe = state => {
   const users = state.get('users', ImmutableMap());
   const me = state.get('me');
 
-  if (!users.get(me)) {
-    return state.set('me', users.first(ImmutableMap()).get('id', null));
+  if (!validUser(users.get(me))) {
+    const nextUser = firstValidUser(state);
+    return state.set('me', nextUser ? nextUser.get('id') : null);
   } else {
     return state;
   }
 };
 
-const setSessionUser = state => state.update('me', null, me => sessionUser || me);
+// Set the user from the session or localStorage, whichever is valid first
+const setSessionUser = state => state.update('me', null, me => {
+  const user = ImmutableList([
+    state.getIn(['users', sessionUser]),
+    state.getIn(['users', me]),
+  ]).find(validUser);
+
+  return user ? user.get('id') : null;
+});
 
 // Upgrade the initial state
 const migrateLegacy = state => {
@@ -63,6 +83,24 @@ const migrateLegacy = state => {
   });
 };
 
+// Checks the state and makes it valid
+const sanitizeState = state => {
+  return state.withMutations(state => {
+    // Remove invalid users, ensure ID match
+    state.update('users', ImmutableMap(), users => (
+      users.filter((user, id) => (
+        validUser(user) && user.get('id') === id
+      ))
+    ));
+    // Remove mismatched tokens
+    state.update('tokens', ImmutableMap(), tokens => (
+      tokens.filter((token, id) => (
+        validId(id) && token.get('access_token') === id
+      ))
+    ));
+  });
+};
+
 const persistAuth = state => localStorage.setItem('soapbox:auth', JSON.stringify(state.toJS()));
 
 const persistSession = state => {
@@ -82,6 +120,7 @@ const initialize = state => {
     maybeShiftMe(state);
     setSessionUser(state);
     migrateLegacy(state);
+    sanitizeState(state);
     persistState(state);
   });
 };
@@ -158,6 +197,8 @@ const reducer = (state, action) => {
     return action.error.response.status === 403 ? deleteToken(state, action.token) : state;
   case SWITCH_ACCOUNT:
     return state.set('me', action.accountId);
+  case ME_FETCH_SKIP:
+    return state.set('me', null);
   default:
     return state;
   }