diff --git a/src/Koogle.Web/Components/Pages/Days/DayEditDialog.razor b/src/Koogle.Web/Components/Pages/Days/DayEditDialog.razor
index b28a89c..383fdcf 100644
--- a/src/Koogle.Web/Components/Pages/Days/DayEditDialog.razor
+++ b/src/Koogle.Web/Components/Pages/Days/DayEditDialog.razor
@@ -46,7 +46,8 @@
                 }
                 else
                 {
-                    <MudChipSet T="Guid" SelectionMode="SelectionMode.MultiSelection" @bind-SelectedValues="_selectedPersonIds" Class="mb-4">
+                    <MudChipSet T="Guid" SelectionMode="SelectionMode.MultiSelection" CheckMark="true" @bind-SelectedValues="_selectedPersonIds" 
+                                Class="mb-4">
                         @foreach (var person in PersonState.Value.Persons.OrderByDescending(p => p.PersonStatus == PersonStatus.Member).ThenBy(p => p.Name))
                         {
                             <MudChip T="Guid"
@@ -64,11 +65,16 @@
                     </MudChipSet>
                 }
             }
+            
+            @if (!string.IsNullOrEmpty(_error))
+            {
+                <MudAlert Severity="Severity.Error">@_error</MudAlert>
+            }
         </MudForm>
     </DialogContent>
     <DialogActions>
         <MudButton OnClick="Cancel">Abbrechen</MudButton>
-        <MudButton Color="Color.Primary" Variant="Variant.Filled" Disabled="!_isValid" OnClick="Submit">
+        <MudButton Color="Color.Primary" Variant="Variant.Filled" OnClick="Submit">
             @(IsEditMode ? "Speichern" : "Erstellen")
         </MudButton>
     </DialogActions>
@@ -82,7 +88,8 @@
     public DaySummaryDto? Day { get; set; }
 
     private MudForm? _form;
-    private bool _isValid;
+    private string _error = string.Empty;
+    private bool _isValid = true;
     private DateTime? _postDate = DateTime.Today;
     private DayStatus _status = DayStatus.New;
     private IReadOnlyCollection<Guid> _selectedPersonIds = [];
@@ -122,7 +129,10 @@
 
     private void Submit()
     {
-        if (!_isValid || _postDate is null) return;
+        Validate();
+
+        if (!_isValid || _postDate is null) 
+            return;
 
         if (IsEditMode)
         {
@@ -144,4 +154,18 @@
             MudDialog?.Close(DialogResult.Ok(dto));
         }
     }
+
+    private void Validate()
+    {
+        _error = "";
+        if (_selectedPersonIds.Count < 2)
+        {
+            _isValid = false;
+            _error = "Es müssen mindestens zwei Teilnehmer ausgewählt werden.";
+            return;
+        }
+
+        _isValid = true;
+    }
+
 }