diff --git a/src/matrix/Session.js b/src/matrix/Session.js
index c5aedcb3..23c9cce6 100644
--- a/src/matrix/Session.js
+++ b/src/matrix/Session.js
@@ -252,7 +252,9 @@ export class Session {
                 this._keyBackup.get().dispose();
                 this._keyBackup.set(undefined);
             }
-            if (this._crossSigning.get()) {
+            const crossSigning = this._crossSigning.get();
+            if (crossSigning) {
+                crossSigning.dispose();
                 this._crossSigning.set(undefined);
             }
             const key = await ssssKeyFromCredential(type, credential, this._storage, this._platform, this._olm);
@@ -317,7 +319,9 @@ export class Session {
             this._keyBackup.get().dispose();
             this._keyBackup.set(undefined);
         }
-        if (this._crossSigning.get()) {
+        const crossSigning = this._crossSigning.get();
+        if (crossSigning) {
+            crossSigning.dispose();
             this._crossSigning.set(undefined);
         }
     }
@@ -374,6 +378,9 @@ export class Session {
                     if (await crossSigning.load(log)) {
                         this._crossSigning.set(crossSigning);
                     }
+                    else {
+                        crossSigning.dispose();
+                    }
                 });
             }
         } catch (err) {
@@ -547,6 +554,7 @@ export class Session {
         this._e2eeAccount = undefined;
         this._callHandler?.dispose();
         this._callHandler = undefined;
+        this._crossSigning.get()?.dispose();
         for (const room of this._rooms.values()) {
             room.dispose();
         }
diff --git a/src/matrix/verification/CrossSigning.ts b/src/matrix/verification/CrossSigning.ts
index 591d57cc..c23c2f54 100644
--- a/src/matrix/verification/CrossSigning.ts
+++ b/src/matrix/verification/CrossSigning.ts
@@ -119,10 +119,8 @@ export class CrossSigning {
         this.deviceId = options.deviceId;
         this.e2eeAccount = options.e2eeAccount
         this.deviceMessageHandler = options.deviceMessageHandler;
-
-        this.deviceMessageHandler.on("message", async ({ unencrypted: unencryptedEvent }) => {
-            this._handleSASDeviceMessage(unencryptedEvent);
-        })
+        this.handleSASDeviceMessage = this.handleSASDeviceMessage.bind(this);
+        this.deviceMessageHandler.on("message", this.handleSASDeviceMessage);
     }
 
     /** @return {boolean} whether cross signing has been enabled on this account */
@@ -209,7 +207,7 @@ export class CrossSigning {
         return this.sasVerificationInProgress;
     }
 
-    private _handleSASDeviceMessage(event: any) {
+    private handleSASDeviceMessage({ unencrypted: event }) {
         const txnId = event.content.transaction_id;
         /**
          * If we receive an event for the current/previously finished 
@@ -376,6 +374,10 @@ export class CrossSigning {
         });
     }
 
+    dispose(): void {
+        this.deviceMessageHandler.off("message", this.handleSASDeviceMessage);
+    }
+
     observeUserTrust(userId: string, log: ILogItem): BaseObservableValue<UserTrust | undefined> {
         const existingValue = this.observedUsers.get(userId);
         if (existingValue) {