diff --git a/src/stores/widgets/StopGapWidgetDriver.ts b/src/stores/widgets/StopGapWidgetDriver.ts
index bf4ee16b5d8..b5609dc5fb9 100644
--- a/src/stores/widgets/StopGapWidgetDriver.ts
+++ b/src/stores/widgets/StopGapWidgetDriver.ts
@@ -414,6 +414,30 @@ export class StopGapWidgetDriver extends WidgetDriver {
         await client._unstable_updateDelayedEvent(delayId, action);
     }
 
+    /**
+     * Implements {@link WidgetDriver#sendToDevice}
+     * Encrypted to-device events are not supported.
+     */
+    public async sendToDevice(
+        eventType: string,
+        encrypted: boolean,
+        contentMap: { [userId: string]: { [deviceId: string]: object } },
+    ): Promise<void> {
+        if (encrypted) throw new Error("Encrypted to-device events are not supported");
+
+        const client = MatrixClientPeg.safeGet();
+        await client.queueToDevice({
+            eventType,
+            batch: Object.entries(contentMap).flatMap(([userId, userContentMap]) =>
+                Object.entries(userContentMap).map(([deviceId, content]) => ({
+                    userId,
+                    deviceId,
+                    payload: content,
+                })),
+            ),
+        });
+    }
+
     private pickRooms(roomIds?: (string | Symbols.AnyRoom)[]): Room[] {
         const client = MatrixClientPeg.get();
         if (!client) throw new Error("Not attached to a client");
diff --git a/test/unit-tests/stores/widgets/StopGapWidgetDriver-test.ts b/test/unit-tests/stores/widgets/StopGapWidgetDriver-test.ts
index 738c3504036..961b702452d 100644
--- a/test/unit-tests/stores/widgets/StopGapWidgetDriver-test.ts
+++ b/test/unit-tests/stores/widgets/StopGapWidgetDriver-test.ts
@@ -170,6 +170,44 @@ describe("StopGapWidgetDriver", () => {
         expect(listener).toHaveBeenCalledWith(openIdUpdate);
     });
 
+    describe("sendToDevice", () => {
+        const contentMap = {
+            "@alice:example.org": {
+                "*": {
+                    hello: "alice",
+                },
+            },
+            "@bob:example.org": {
+                bobDesktop: {
+                    hello: "bob",
+                },
+            },
+        };
+
+        let driver: WidgetDriver;
+
+        beforeEach(() => {
+            driver = mkDefaultDriver();
+        });
+
+        it("sends unencrypted messages", async () => {
+            await driver.sendToDevice("org.example.foo", false, contentMap);
+            expect(client.queueToDevice).toHaveBeenCalledWith({
+                eventType: "org.example.foo",
+                batch: [
+                    { deviceId: "*", payload: { hello: "alice" }, userId: "@alice:example.org" },
+                    { deviceId: "bobDesktop", payload: { hello: "bob" }, userId: "@bob:example.org" },
+                ],
+            });
+        });
+
+        it("raises an error if encrypted", async () => {
+            await expect(driver.sendToDevice("org.example.foo", true, contentMap)).rejects.toThrow(
+                "Encrypted to-device events are not supported",
+            );
+        });
+    });
+
     describe("getTurnServers", () => {
         let driver: WidgetDriver;