diff --git a/electron-projects/ucap-webmessenger-electron/src/index.ts b/electron-projects/ucap-webmessenger-electron/src/index.ts
index 313a4149..08338353 100644
--- a/electron-projects/ucap-webmessenger-electron/src/index.ts
+++ b/electron-projects/ucap-webmessenger-electron/src/index.ts
@@ -600,12 +600,21 @@ ipcMain.on(
 ipcMain.on(
   FileChannel.SelectSaveFilePath,
   (event: IpcMainEvent, ...args: any[]) => {
+    const defaultPath = args[0];
+    const ext = path.extname(defaultPath);
     dialog
-      .showSaveDialog({ defaultPath: args[0] })
+      .showSaveDialog({
+        defaultPath
+      })
       .then(obj => {
+        const filePath =
+          '' !== ext && '' === path.extname(obj.filePath)
+            ? `${obj.filePath}${ext}`
+            : obj.filePath;
+
         event.returnValue = {
           canceled: obj.canceled,
-          filePath: obj.filePath
+          filePath
         };
       })
       .catch(obj => {