diff --git a/src/Avalonia.Controls/DateTimePickers/TimePickerPresenter.cs b/src/Avalonia.Controls/DateTimePickers/TimePickerPresenter.cs
index 56f8875739d..4719fa69a2a 100644
--- a/src/Avalonia.Controls/DateTimePickers/TimePickerPresenter.cs
+++ b/src/Avalonia.Controls/DateTimePickers/TimePickerPresenter.cs
@@ -191,7 +191,7 @@ protected override void OnConfirmed()
 
             if (ClockIdentifier == "12HourClock")
             {
-                hr = per == 1 ? hr + 12 : per == 0 && hr == 12 ? 0 : hr;
+                hr = per == 1 ? (hr == 12) ? 12 : hr + 12 : per == 0 && hr == 12 ? 0 : hr;
             }
 
             Time = new TimeSpan(hr, min, 0);