diff --git a/spec/unit/rust-crypto/rust-crypto.spec.ts b/spec/unit/rust-crypto/rust-crypto.spec.ts
index 22640b9bf..ec816014f 100644
--- a/spec/unit/rust-crypto/rust-crypto.spec.ts
+++ b/spec/unit/rust-crypto/rust-crypto.spec.ts
@@ -498,7 +498,7 @@ describe("RustCrypto", () => {
             [RustSdkCryptoJs.ShieldColor.Red, EventShieldColour.RED],
         ])("gets the right shield color (%i)", async (rustShield, expectedShield) => {
             const mockEncryptionInfo = {
-                shieldState: jest.fn().mockReturnValue({ color: rustShield, message: null }),
+                shieldState: jest.fn().mockReturnValue({ color: rustShield, message: undefined }),
             } as unknown as RustSdkCryptoJs.EncryptionInfo;
             olmMachine.getRoomEventEncryptionInfo.mockResolvedValue(mockEncryptionInfo);
 
@@ -509,7 +509,7 @@ describe("RustCrypto", () => {
         });
 
         it.each([
-            [null, null],
+            [undefined, null],
             ["Encrypted by an unverified user.", EventShieldReason.UNVERIFIED_IDENTITY],
             ["Encrypted by a device not verified by its owner.", EventShieldReason.UNSIGNED_DEVICE],
             [
diff --git a/src/rust-crypto/RoomEncryptor.ts b/src/rust-crypto/RoomEncryptor.ts
index 3863c8592..166f9bb93 100644
--- a/src/rust-crypto/RoomEncryptor.ts
+++ b/src/rust-crypto/RoomEncryptor.ts
@@ -65,15 +65,14 @@ export class RoomEncryptor {
      * @param member - new membership state
      */
     public onRoomMembership(member: RoomMember): void {
-        this.prefixedLogger.debug(`${member.membership} event for ${member.userId}`);
-
         if (
             member.membership == "join" ||
             (member.membership == "invite" && this.room.shouldEncryptForInvitedMembers())
         ) {
             // make sure we are tracking the deviceList for this user
-            this.prefixedLogger.debug(`starting to track devices for: ${member.userId}`);
-            this.olmMachine.updateTrackedUsers([new UserId(member.userId)]);
+            this.olmMachine.updateTrackedUsers([new UserId(member.userId)]).catch((e) => {
+                this.prefixedLogger.error("Unable to update tracked users", e);
+            });
         }
 
         // TODO: handle leaves (including our own)
diff --git a/src/rust-crypto/backup.ts b/src/rust-crypto/backup.ts
index f115fee02..9ecb68b35 100644
--- a/src/rust-crypto/backup.ts
+++ b/src/rust-crypto/backup.ts
@@ -82,7 +82,7 @@ export class RustBackupManager extends TypedEventEmitter<RustBackupCryptoEvents,
      * Get the backup version we are currently backing up to, if any
      */
     public async getActiveBackupVersion(): Promise<string | null> {
-        if (!this.olmMachine.isBackupEnabled()) return null;
+        if (!(await this.olmMachine.isBackupEnabled())) return null;
         return this.activeBackupVersion;
     }
 
diff --git a/src/rust-crypto/rust-crypto.ts b/src/rust-crypto/rust-crypto.ts
index 46fe69702..622bae28d 100644
--- a/src/rust-crypto/rust-crypto.ts
+++ b/src/rust-crypto/rust-crypto.ts
@@ -1223,10 +1223,6 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, RustCryptoEv
 
         // start tracking devices for any users already known to be in this room.
         const members = await room.getEncryptionTargetMembers();
-        logger.debug(
-            `[${room.roomId} encryption] starting to track devices for: `,
-            members.map((u) => `${u.userId} (${u.membership})`),
-        );
         await this.olmMachine.updateTrackedUsers(members.map((u) => new RustSdkCryptoJs.UserId(u.userId)));
     }
 
@@ -1518,7 +1514,10 @@ class EventDecryptor {
     public constructor(private readonly olmMachine: RustSdkCryptoJs.OlmMachine, private readonly crypto: RustCrypto) {}
 
     public async attemptEventDecryption(event: MatrixEvent): Promise<IEventDecryptionResult> {
-        logger.info("Attempting decryption of event", event);
+        logger.info(
+            `Attempting decryption of event ${event.getId()} in ${event.getRoomId()} from ${event.getSender()}`,
+        );
+
         // add the event to the pending list *before* attempting to decrypt.
         // then, if the key turns up while decryption is in progress (and
         // decryption fails), we will schedule a retry.
@@ -1691,7 +1690,7 @@ function rustEncryptionInfoToJsEncryptionInfo(
     }
 
     let shieldReason: EventShieldReason | null;
-    if (shieldState.message === null) {
+    if (shieldState.message === undefined) {
         shieldReason = null;
     } else if (shieldState.message === "Encrypted by an unverified user.") {
         // this case isn't actually used with lax shield semantics.