diff --git a/src/client.ts b/src/client.ts
index 7b8514034..5ea515fe9 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -4131,12 +4131,12 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         roomId: string,
         userId: string | string[],
         powerLevel: number,
-        event: MatrixEvent,
+        event: MatrixEvent | null,
     ): Promise<ISendEventResponse> {
         let content = {
             users: {} as Record<string, number>,
         };
-        if (event.getType() === EventType.RoomPowerLevels) {
+        if (event?.getType() === EventType.RoomPowerLevels) {
             // take a copy of the content to ensure we don't corrupt
             // existing client state with a failed power level change
             content = utils.deepCopy(event.getContent());
diff --git a/src/crypto/index.ts b/src/crypto/index.ts
index 4387dcd06..550087222 100644
--- a/src/crypto/index.ts
+++ b/src/crypto/index.ts
@@ -151,7 +151,7 @@ export interface ICryptoCallbacks {
         requestId: string,
         secretName: string,
         deviceTrust: DeviceTrustLevel,
-    ) => Promise<string>;
+    ) => Promise<string | undefined>;
     getDehydrationKey?: (keyInfo: ISecretStorageKeyInfo, checkFunc: (key: Uint8Array) => void) => Promise<Uint8Array>;
     getBackupKey?: () => Promise<Uint8Array>;
 }