diff --git a/src/main/modules/app-window/app-window.ts b/src/main/modules/app-window/app-window.ts
index 8bc944f..202a62b 100644
--- a/src/main/modules/app-window/app-window.ts
+++ b/src/main/modules/app-window/app-window.ts
@@ -59,6 +59,7 @@ export abstract class AppWindow implements IAppWindow {
     this.sessionHelper.setCsp(this._window, this.getCsp());
 
     this._window.on('closed', () => {
+      this.onClosed();
       this._window = null;
     });
 
@@ -97,5 +98,7 @@ export abstract class AppWindow implements IAppWindow {
     event.preventDefault();
   }
 
+  protected onClosed(): void {}
+
   protected abstract load(window: BrowserWindow): Promise<void>;
 }
diff --git a/src/main/modules/app-window/site-app-window.ts b/src/main/modules/app-window/site-app-window.ts
index 1309c66..9328678 100644
--- a/src/main/modules/app-window/site-app-window.ts
+++ b/src/main/modules/app-window/site-app-window.ts
@@ -24,4 +24,8 @@ export abstract class SiteAppWindow extends UrlAppWindow implements ISiteAppWind
   public acquireLock(): Promise<Mutex.ReleaseFunction> {
     return this.windowLock.acquire();
   }
+
+  protected onClosed(): void {
+    this.windowLock.reset();
+  }
 }
diff --git a/src/main/modules/mutex/i-mutex.d.ts b/src/main/modules/mutex/i-mutex.d.ts
index b6a9fe4..20f5060 100644
--- a/src/main/modules/mutex/i-mutex.d.ts
+++ b/src/main/modules/mutex/i-mutex.d.ts
@@ -11,6 +11,16 @@ interface IMutex {
    */
   acquire(): Promise<Mutex.ReleaseFunction>;
 
+  /**
+   * release the lock and execute the next consumer.
+   */
+  release(): void;
+
+  /**
+   * release the lock and do not allow any current consumers to execute.
+   */
+  reset(): void;
+
   isLocked(): boolean;
 }
 
diff --git a/src/main/modules/mutex/simple-mutex.ts b/src/main/modules/mutex/simple-mutex.ts
index a313910..d7c62b9 100644
--- a/src/main/modules/mutex/simple-mutex.ts
+++ b/src/main/modules/mutex/simple-mutex.ts
@@ -21,6 +21,16 @@ export class SimpleMutex implements IMutex {
     });
   }
 
+  public release(): void {
+    this.locked = false;
+    this.dispatch();
+  }
+
+  public reset(): void {
+    this.queue = [];
+    this.locked = false;
+  }
+
   public isLocked(): boolean {
     return this.locked;
   }
@@ -37,13 +47,13 @@ export class SimpleMutex implements IMutex {
     if (!nextResolve) {
       return;
     }
+    // lock the resource
     this.locked = true;
 
     // this is the function which gets called by the consumer to release the lock
     // it also dispatches the next consumer
     const releaseFunction = (): void => {
-      this.locked = false;
-      this.dispatch();
+      this.release();
     };
 
     // lock the resource and resolve the promise so the consumer can do its thing