diff --git a/src/components/structures/MatrixChat.tsx b/src/components/structures/MatrixChat.tsx
index 532b1f4225..d9ed7d061b 100644
--- a/src/components/structures/MatrixChat.tsx
+++ b/src/components/structures/MatrixChat.tsx
@@ -84,6 +84,7 @@ import {replaceableComponent} from "../../utils/replaceableComponent";
 import RoomListStore from "../../stores/room-list/RoomListStore";
 import {RoomUpdateCause} from "../../stores/room-list/models";
 import defaultDispatcher from "../../dispatcher/dispatcher";
+import SecurityCustomisations from "../../customisations/Security";
 
 /** constants for MatrixChat.state.view */
 export enum Views {
@@ -395,7 +396,11 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
 
         const crossSigningIsSetUp = cli.getStoredCrossSigningForUser(cli.getUserId());
         if (crossSigningIsSetUp) {
-            this.setStateForNewView({ view: Views.COMPLETE_SECURITY });
+            if (SecurityCustomisations.SHOW_ENCRYPTION_SETUP_UI === false) {
+                this.onLoggedIn();
+            } else {
+                this.setStateForNewView({view: Views.COMPLETE_SECURITY});
+            }
         } else if (await cli.doesServerSupportUnstableFeature("org.matrix.e2e_cross_signing")) {
             this.setStateForNewView({ view: Views.E2E_SETUP });
         } else {
diff --git a/src/customisations/Security.ts b/src/customisations/Security.ts
index 96b5b62cdb..e215c5cb24 100644
--- a/src/customisations/Security.ts
+++ b/src/customisations/Security.ts
@@ -74,8 +74,20 @@ export interface ISecurityCustomisations {
     catchAccessSecretStorageError?: typeof catchAccessSecretStorageError,
     setupEncryptionNeeded?: typeof setupEncryptionNeeded,
     getDehydrationKey?: typeof getDehydrationKey,
+
+    /**
+     * When false, disables the post-login UI from showing. If there's
+     * an error during setup, that will be shown to the user.
+     *
+     * Note: when this is set to false then the app will assume the user's
+     * encryption is set up some other way which would circumvent the default
+     * UI, such as by presenting alternative UI.
+     */
+    SHOW_ENCRYPTION_SETUP_UI?: boolean, // default true
 }
 
 // A real customisation module will define and export one or more of the
 // customisation points that make up `ISecurityCustomisations`.
-export default {} as ISecurityCustomisations;
+export default {
+    SHOW_ENCRYPTION_SETUP_UI: true,
+} as ISecurityCustomisations;