diff --git a/OpenUtau/Strings/Strings.axaml b/OpenUtau/Strings/Strings.axaml
index 4aa620c1e..1e5614e7e 100644
--- a/OpenUtau/Strings/Strings.axaml
+++ b/OpenUtau/Strings/Strings.axaml
@@ -99,8 +99,9 @@ OpenUtau aims to be an open source editing environment for UTAU community, with
   <system:String x:Key="dialogs.installdependency.message">Installing </system:String>
   <system:String x:Key="dialogs.installdll.caption">Installing phonemizer</system:String>
   <system:String x:Key="dialogs.installdll.message">Installing </system:String>
-  <system:String x:Key="dialogs.merge.caption">Merging Parts</system:String>
-  <system:String x:Key="dialogs.merge.multitracks">Parts on different tracks cannot be merged.</system:String>
+  <system:String x:Key="dialogs.mergeparts.caption">Merging Parts</system:String>
+  <system:String x:Key="dialogs.mergeparts.multitracks">Parts on different tracks cannot be merged.</system:String>
+  <system:String x:Key="dialogs.mergeparts.overlap">Merged part will contain overlapping notes. Are you sure to continue?</system:String>
   <system:String x:Key="dialogs.splitpart.caption">Splitting Part</system:String>
   <system:String x:Key="dialogs.splitpart.intheway">There are one or more note(s) overlapping with the playhead.
 Do you want to continue by splitting at the nearest position after current playhead with no notes in the way?</system:String>
diff --git a/OpenUtau/Views/MainWindow.axaml.cs b/OpenUtau/Views/MainWindow.axaml.cs
index 5ea4cdb0c..1ffc9ca50 100644
--- a/OpenUtau/Views/MainWindow.axaml.cs
+++ b/OpenUtau/Views/MainWindow.axaml.cs
@@ -81,7 +81,7 @@ public MainWindow() {
             PartGotoFileCommand = ReactiveCommand.Create<UPart>(part => GotoFile(part));
             PartReplaceAudioCommand = ReactiveCommand.Create<UPart>(part => ReplaceAudio(part));
             PartTranscribeCommand = ReactiveCommand.Create<UPart>(part => Transcribe(part));
-            PartMergeCommand = ReactiveCommand.Create<UPart>(part => MergePart(part));
+            PartMergeCommand = ReactiveCommand.Create<UPart>(async part => await MergePart(part));
             PartSplitCommand = ReactiveCommand.Create<UPart>(async part =>  await SplitPart(part));
 
             AddHandler(DragDrop.DropEvent, OnDrop);
@@ -1568,17 +1568,17 @@ public void OnWelcomeRecovery(object sender, RoutedEventArgs args) {
             viewModel.Page = 1;
         }
 
-        void MergePart(UPart part) {
+        async Task MergePart(UPart part) {
             List<UPart> selectedParts = viewModel.TracksViewModel.SelectedParts;
-            if (!selectedParts.All(p => p.trackNo.Equals(part.trackNo))) {
+            if (selectedParts.Count <= 1) { return; }
+            if (selectedParts.Any(p => p.trackNo != part.trackNo)) {
                 _ = MessageBox.Show(
                     this,
-                    ThemeManager.GetString("dialogs.merge.multitracks"),
-                    ThemeManager.GetString("dialogs.merge.caption"),
+                    ThemeManager.GetString("dialogs.mergeparts.multitracks"),
+                    ThemeManager.GetString("dialogs.mergeparts.caption"),
                     MessageBox.MessageBoxButtons.Ok);
                 return;
             }
-            if (selectedParts.Count() <= 1) { return; }
             List<UVoicePart> voiceParts = [];
             foreach (UPart p in selectedParts) {
                 if (p is UVoicePart vp) {
@@ -1625,6 +1625,14 @@ void MergePart(UPart part) {
                 SkipPhonemizer = false
             };
             mergedPart.Validate(options, DocManager.Inst.Project, DocManager.Inst.Project.tracks[part.trackNo]);
+            if (mergedPart.notes.Any(n => n.OverlapError)) {
+                var res = await MessageBox.Show(
+                    this,
+                    ThemeManager.GetString("dialogs.mergeparts.overlap"),
+                    ThemeManager.GetString("dialogs.mergeparts.caption"),
+                    MessageBox.MessageBoxButtons.YesNo);
+                if (res == MessageBox.MessageBoxResult.No) { return; }
+            }
             DocManager.Inst.StartUndoGroup("command.part.edit");
             for (int i = selectedParts.Count - 1; i >= 0; i--) {
                 // The index will shift by removing a part on each loop