diff --git a/src/features/preview.ts b/src/features/preview.ts
index e0f6dd06..ec2f5c25 100644
--- a/src/features/preview.ts
+++ b/src/features/preview.ts
@@ -229,6 +229,9 @@ export class AsciidocPreview extends Disposable implements WebviewResourceProvid
     this.editor.dispose()
 
     disposeAll(this.disposables)
+
+    clearTimeout(this.throttleTimer)
+    this.throttleTimer = undefined
   }
 
   // This method is invoked evrytime there is a document update
@@ -358,6 +361,10 @@ export class AsciidocPreview extends Disposable implements WebviewResourceProvid
     clearTimeout(this.throttleTimer)
     this.throttleTimer = undefined
 
+    if (this._disposed) {
+      return
+    }
+
     const document = await vscode.workspace.openTextDocument(resource)
     if (!this.forceUpdate && this.currentVersion &&
       this.currentVersion.resource.fsPath === resource.fsPath &&