diff --git a/web/redux/primary-identity-public-key-reducer.js b/web/redux/primary-identity-public-key-reducer.js
new file mode 100644
--- /dev/null
+++ b/web/redux/primary-identity-public-key-reducer.js
@@ -0,0 +1,29 @@
+// @flow
+
+import {
+  logOutActionTypes,
+  deleteAccountActionTypes,
+} from 'lib/actions/user-actions';
+import { setNewSessionActionType } from 'lib/utils/action-utils.js';
+
+import type { Action } from './redux-setup.js';
+
+const setPrimaryIdentityPublicKey = 'SET_PRIMARY_IDENTITY_PUBLIC_KEY';
+function reducePrimaryIdentityPublicKey(
+  state: ?string,
+  action: Action,
+): ?string {
+  if (action.type === setPrimaryIdentityPublicKey) {
+    return action.payload;
+  } else if (
+    action.type === logOutActionTypes.success ||
+    action.type === deleteAccountActionTypes.success ||
+    (action.type === setNewSessionActionType &&
+      action.payload.sessionChange.cookieInvalidated)
+  ) {
+    return null;
+  }
+  return state;
+}
+
+export { setPrimaryIdentityPublicKey, reducePrimaryIdentityPublicKey };
diff --git a/web/redux/redux-setup.js b/web/redux/redux-setup.js
--- a/web/redux/redux-setup.js
+++ b/web/redux/redux-setup.js
@@ -37,6 +37,10 @@
 } from './action-types';
 import { reduceDeviceID } from './device-id-reducer';
 import reduceNavInfo from './nav-reducer';
+import {
+  reducePrimaryIdentityPublicKey,
+  setPrimaryIdentityPublicKey,
+} from './primary-identity-public-key-reducer';
 import { getVisibility } from './visibility';
 
 export type WindowDimensions = { width: number, height: number };
@@ -85,7 +89,8 @@
   | {
       type: 'SET_DEVICE_ID',
       payload: string,
-    };
+    }
+  | { +type: 'SET_PRIMARY_IDENTITY_PUBLIC_KEY', payload: ?string };
 
 export function reducer(oldState: AppState | void, action: Action): AppState {
   invariant(oldState, 'should be set');
@@ -134,7 +139,8 @@
 
   if (
     action.type !== updateNavInfoActionType &&
-    action.type !== setDeviceIDActionType
+    action.type !== setDeviceIDActionType &&
+    action.type !== setPrimaryIdentityPublicKey
   ) {
     state = baseReducer(state, action).state;
   }
@@ -147,6 +153,10 @@
       state.threadStore.threadInfos,
     ),
     deviceID: reduceDeviceID(state.deviceID, action),
+    primaryIdentityPublicKey: reducePrimaryIdentityPublicKey(
+      state.primaryIdentityPublicKey,
+      action,
+    ),
   };
 
   return validateState(oldState, state);