Index: Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingCalculationContextNodePresenter.cs
===================================================================
diff -u -r0758a103361e8067e8b56eec6cc28ff0c6eba12f -r94ad8ac133939b11df035a772cba786e53d7c20d
--- Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingCalculationContextNodePresenter.cs	(.../PipingCalculationContextNodePresenter.cs)	(revision 0758a103361e8067e8b56eec6cc28ff0c6eba12f)
+++ Ringtoets/Piping/src/Ringtoets.Piping.Forms/NodePresenters/PipingCalculationContextNodePresenter.cs	(.../PipingCalculationContextNodePresenter.cs)	(revision 94ad8ac133939b11df035a772cba786e53d7c20d)
@@ -12,6 +12,7 @@
 using Ringtoets.Piping.Forms.Properties;
 using Ringtoets.Piping.Service;
 using RingtoetsFormsResources = Ringtoets.Common.Forms.Properties.Resources;
+using BaseResources = Core.Common.Base.Properties.Resources;
 
 namespace Ringtoets.Piping.Forms.NodePresenters
 {
@@ -122,11 +123,7 @@
             var clearOutputItem = new StrictContextMenuItem(Resources.Clear_output,
                                                             null,
                                                             RingtoetsFormsResources.ClearIcon,
-                                                            (o, args) =>
-                                                            {
-                                                                calculation.ClearOutput();
-                                                                calculation.NotifyObservers();
-                                                            });
+                                                            (o, args) => ClearOutput(calculation));
 
             if (!calculation.HasOutput)
             {
@@ -151,5 +148,15 @@
                 .AddPropertiesItem()
                 .Build();
         }
+            
+        private static void ClearOutput(PipingCalculation calculation)
+        {
+            if (MessageBox.Show(Resources.PipingCalculationContextNodePresenter_GetContextMenu_Are_you_sure_clear_output, BaseResources.Confirm, MessageBoxButtons.OKCancel) != DialogResult.OK)
+            {
+                return;
+            }
+            calculation.ClearOutput();
+            calculation.NotifyObservers();
+        }
     }
 }
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