diff --git a/spec/unit/rust-crypto/verification.spec.ts b/spec/unit/rust-crypto/verification.spec.ts
index 90f9e846b32..6bf3df1a026 100644
--- a/spec/unit/rust-crypto/verification.spec.ts
+++ b/spec/unit/rust-crypto/verification.spec.ts
@@ -62,9 +62,13 @@ describe("VerificationRequest", () => {
 
     describe("startVerification", () => {
         let request: RustVerificationRequest;
+        let machine: Mocked<RustSdkCryptoJs.OlmMachine>;
+        let inner: Mocked<RustSdkCryptoJs.VerificationRequest>;
 
         beforeEach(() => {
-            request = makeTestRequest();
+            inner = makeMockedInner();
+            machine = { getDevice: jest.fn() } as unknown as Mocked<RustSdkCryptoJs.OlmMachine>;
+            request = makeTestRequest(inner, machine);
         });
 
         it("does not permit methods other than SAS", async () => {
@@ -73,7 +77,15 @@ describe("VerificationRequest", () => {
             );
         });
 
+        it("raises an error if the other device is unknown", async () => {
+            await expect(request.startVerification("m.sas.v1")).rejects.toThrow(
+                "startVerification(): other device is unknown",
+            );
+        });
+
         it("raises an error if starting verification does not produce a verifier", async () => {
+            jest.spyOn(inner, "otherDeviceId", "get").mockReturnValue(new RustSdkCryptoJs.DeviceId("other_device"));
+            machine.getDevice.mockResolvedValue({} as RustSdkCryptoJs.Device);
             await expect(request.startVerification("m.sas.v1")).rejects.toThrow(
                 "Still no verifier after startSas() call",
             );
@@ -118,11 +130,13 @@ describe("isVerificationEvent", () => {
 /** build a RustVerificationRequest with default parameters */
 function makeTestRequest(
     inner?: RustSdkCryptoJs.VerificationRequest,
+    olmMachine?: RustSdkCryptoJs.OlmMachine,
     outgoingRequestProcessor?: OutgoingRequestProcessor,
 ): RustVerificationRequest {
     inner ??= makeMockedInner();
+    olmMachine ??= {} as RustSdkCryptoJs.OlmMachine;
     outgoingRequestProcessor ??= {} as OutgoingRequestProcessor;
-    return new RustVerificationRequest(inner, outgoingRequestProcessor, []);
+    return new RustVerificationRequest(olmMachine, inner, outgoingRequestProcessor, []);
 }
 
 /** Mock up a rust-side VerificationRequest */
@@ -133,5 +147,8 @@ function makeMockedInner(): Mocked<RustSdkCryptoJs.VerificationRequest> {
         phase: jest.fn().mockReturnValue(RustSdkCryptoJs.VerificationRequestPhase.Created),
         isPassive: jest.fn().mockReturnValue(false),
         timeRemainingMillis: jest.fn(),
+        get otherDeviceId() {
+            return undefined;
+        },
     } as unknown as Mocked<RustSdkCryptoJs.VerificationRequest>;
 }
diff --git a/src/rust-crypto/rust-crypto.ts b/src/rust-crypto/rust-crypto.ts
index de7b368b4eb..c32662a0f69 100644
--- a/src/rust-crypto/rust-crypto.ts
+++ b/src/rust-crypto/rust-crypto.ts
@@ -940,6 +940,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
             .map(
                 (request) =>
                     new RustVerificationRequest(
+                        this.olmMachine,
                         request,
                         this.outgoingRequestProcessor,
                         this._supportedVerificationMethods,
@@ -970,6 +971,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
 
         if (request) {
             return new RustVerificationRequest(
+                this.olmMachine,
                 request,
                 this.outgoingRequestProcessor,
                 this._supportedVerificationMethods,
@@ -1005,6 +1007,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 methods,
             );
             return new RustVerificationRequest(
+                this.olmMachine,
                 request,
                 this.outgoingRequestProcessor,
                 this._supportedVerificationMethods,
@@ -1080,6 +1083,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 );
             await this.outgoingRequestProcessor.makeOutgoingRequest(outgoingRequest);
             return new RustVerificationRequest(
+                this.olmMachine,
                 request,
                 this.outgoingRequestProcessor,
                 this._supportedVerificationMethods,
@@ -1118,6 +1122,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 );
             await this.outgoingRequestProcessor.makeOutgoingRequest(outgoingRequest);
             return new RustVerificationRequest(
+                this.olmMachine,
                 request,
                 this.outgoingRequestProcessor,
                 this._supportedVerificationMethods,
@@ -1405,7 +1410,12 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
         if (request) {
             this.emit(
                 CryptoEvent.VerificationRequestReceived,
-                new RustVerificationRequest(request, this.outgoingRequestProcessor, this._supportedVerificationMethods),
+                new RustVerificationRequest(
+                    this.olmMachine,
+                    request,
+                    this.outgoingRequestProcessor,
+                    this._supportedVerificationMethods,
+                ),
             );
         }
     }
@@ -1622,6 +1632,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
                 this.emit(
                     CryptoEvent.VerificationRequestReceived,
                     new RustVerificationRequest(
+                        this.olmMachine,
                         request,
                         this.outgoingRequestProcessor,
                         this._supportedVerificationMethods,
diff --git a/src/rust-crypto/verification.ts b/src/rust-crypto/verification.ts
index 4ce5a6c380a..bac4694441c 100644
--- a/src/rust-crypto/verification.ts
+++ b/src/rust-crypto/verification.ts
@@ -57,11 +57,13 @@ export class RustVerificationRequest
     /**
      * Construct a new RustVerificationRequest to wrap the rust-level `VerificationRequest`.
      *
-     * @param inner - VerificationRequest from the Rust SDK
-     * @param outgoingRequestProcessor - `OutgoingRequestProcessor` to use for making outgoing HTTP requests
-     * @param supportedVerificationMethods - Verification methods to use when `accept()` is called
+     * @param olmMachine - The `OlmMachine` from the underlying rust crypto sdk.
+     * @param inner - VerificationRequest from the Rust SDK.
+     * @param outgoingRequestProcessor - `OutgoingRequestProcessor` to use for making outgoing HTTP requests.
+     * @param supportedVerificationMethods - Verification methods to use when `accept()` is called.
      */
     public constructor(
+        private readonly olmMachine: RustSdkCryptoJs.OlmMachine,
         private readonly inner: RustSdkCryptoJs.VerificationRequest,
         private readonly outgoingRequestProcessor: OutgoingRequestProcessor,
         private readonly supportedVerificationMethods: string[],
@@ -135,6 +137,15 @@ export class RustVerificationRequest
         return this.inner.otherDeviceId?.toString();
     }
 
+    /** Get the other device involved in the verification, if it is known */
+    private async getOtherDevice(): Promise<undefined | RustSdkCryptoJs.Device> {
+        const otherDeviceId = this.inner.otherDeviceId;
+        if (!otherDeviceId) {
+            return undefined;
+        }
+        return await this.olmMachine.getDevice(this.inner.otherUserId, otherDeviceId, 5);
+    }
+
     /** True if the other party in this request is one of this user's own devices. */
     public get isSelfVerification(): boolean {
         return this.inner.isSelfVerification();
@@ -322,6 +333,11 @@ export class RustVerificationRequest
             throw new Error(`Unsupported verification method ${method}`);
         }
 
+        // make sure that we have a list of the other user's devices (workaround https://github.com/matrix-org/matrix-rust-sdk/issues/2896)
+        if (!(await this.getOtherDevice())) {
+            throw new Error("startVerification(): other device is unknown");
+        }
+
         const res:
             | [RustSdkCryptoJs.Sas, RustSdkCryptoJs.RoomMessageRequest | RustSdkCryptoJs.ToDeviceRequest]
             | undefined = await this.inner.startSas();
@@ -392,6 +408,11 @@ export class RustVerificationRequest
      * Implementation of {@link Crypto.VerificationRequest#generateQRCode}.
      */
     public async generateQRCode(): Promise<Buffer | undefined> {
+        // make sure that we have a list of the other user's devices (workaround https://github.com/matrix-org/matrix-rust-sdk/issues/2896)
+        if (!(await this.getOtherDevice())) {
+            throw new Error("generateQRCode(): other device is unknown");
+        }
+
         const innerVerifier: RustSdkCryptoJs.Qr | undefined = await this.inner.generateQrCode();
         // If we are unable to generate a QRCode, we return undefined
         if (!innerVerifier) return;