diff --git a/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs b/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
index 55f8c5f..7277f72 100644
--- a/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/Islands/DetailsIslandViewModel.cs
@@ -58,6 +58,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     [ObservableProperty] private string? _model;
     [ObservableProperty] private string? _worktreePath;
     [ObservableProperty] private string? _worktreeBaseCommit;
+    [ObservableProperty] private string? _worktreeStateLabel;
     [ObservableProperty] private string? _branchLine;
     [ObservableProperty] private int _turns;
     [ObservableProperty] private int _tokens;
@@ -231,6 +232,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
             Notes = "";
             Model = null;
             WorktreePath = null;
+            WorktreeStateLabel = null;
             BranchLine = null;
             AgentStatusLabel = "Idle";
             LatestRunSessionId = null;
@@ -260,6 +262,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
             Notes = entity.Notes ?? "";
             Model = entity.Model;
             WorktreePath = entity.Worktree?.Path;
+            WorktreeStateLabel = entity.Worktree?.State.ToString();
             BranchLine = entity.Worktree is { } w ? $"{w.BranchName} \u2190 main" : null;
             AgentStatusLabel = entity.Status.ToString();
 
@@ -292,6 +295,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
 
             WorktreePath = entity.Worktree?.Path;
             WorktreeBaseCommit = entity.Worktree?.BaseCommit;
+            WorktreeStateLabel = entity.Worktree?.State.ToString();
             BranchLine = entity.Worktree is { } w ? $"{w.BranchName} ← main" : null;
             AgentStatusLabel = entity.Status.ToString();
             if (Task is { } row && entity.Worktree?.DiffStat is { } stat)
@@ -343,6 +347,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         ApproveMergeCommand.NotifyCanExecuteChanged();
     }
 
+    partial void OnWorktreeStateLabelChanged(string? value)
+    {
+        ApproveMergeCommand.NotifyCanExecuteChanged();
+    }
+
     [RelayCommand]
     private async System.Threading.Tasks.Task SendPromptAsync()
     {
@@ -398,7 +407,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     }
 
     private bool CanMerge() =>
-        Task != null && _worker.IsConnected && WorktreePath != null;
+        Task != null && _worker.IsConnected && WorktreePath != null && WorktreeStateLabel == "Active";
 
     [RelayCommand]
     private async System.Threading.Tasks.Task StopAsync()