..

QuickLook.Plugin/QuickLook.Plugin.PDFViewer/PdfFile.cs

@@ -23,11 +23,18 @@ namespace QuickLook.Plugin.PDFViewer
 
         public void Dispose()
         {
+            GC.SuppressFinalize(this);
+
             LibMuPdf.NativeMethods.CloseDocument(_doc);
             LibMuPdf.NativeMethods.CloseStream(_stm);
             LibMuPdf.NativeMethods.FreeContext(_ctx);
         }
 
+        ~PdfFile()
+        {
+            Dispose();
+        }
+
         public bool IsLastPage(int pageId)
         {
             return pageId >= TotalPages;