diff --git a/samples/Console32/Program.cs b/samples/Console32/Program.cs
index b200b7a..05439c8 100644
--- a/samples/Console32/Program.cs
+++ b/samples/Console32/Program.cs
@@ -15,18 +15,18 @@ namespace SampleConsole
       var twain = new TwainSession(Assembly.GetExecutingAssembly().Location);
       twain.StateChanged += Twain_StateChanged;
 
-      var hwnd = IntPtr.Zero;
+      var hwnd = IntPtr.Zero; // required for windows
       var rc = twain.DGControl.Parent.OpenDSM(ref hwnd);
       Debug.WriteLine($"OpenDSM={rc}");
 
-      if (rc == TWAINWorkingGroup.STS.SUCCESS)
+      if (rc == STS.SUCCESS)
       {
         Debug.WriteLine($"CloseDSM={rc}");
         rc = twain.DGControl.Parent.CloseDSM(ref hwnd);
       }
     }
 
-    private static void Twain_StateChanged(TwainSession session, TWAINWorkingGroup.STATE state)
+    private static void Twain_StateChanged(TwainSession session, STATE state)
     {
       Console.WriteLine($"State changed to {state}");
     }
diff --git a/samples/WinForm32/Form1.cs b/samples/WinForm32/Form1.cs
index 6c568c9..5e0aaaa 100644
--- a/samples/WinForm32/Form1.cs
+++ b/samples/WinForm32/Form1.cs
@@ -1,5 +1,6 @@
 using NTwain;
 using System;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.Reflection;
 using System.Windows.Forms;
@@ -21,7 +22,7 @@ namespace WinForm32
       twain.StateChanged += Twain_StateChanged;
     }
 
-    private static void Twain_StateChanged(TwainSession session, TWAINWorkingGroup.STATE state)
+    private static void Twain_StateChanged(TwainSession session, STATE state)
     {
       Console.WriteLine($"State changed to {state}");
     }
@@ -34,12 +35,14 @@ namespace WinForm32
       var hwnd = this.Handle;
       var rc = twain.DGControl.Parent.OpenDSM(ref hwnd);
       Debug.WriteLine($"OpenDSM={rc}");
+    }
 
-      if (rc == TWAINWorkingGroup.STS.SUCCESS)
-      {
-        Debug.WriteLine($"CloseDSM={rc}");
-        rc = twain.DGControl.Parent.CloseDSM(ref hwnd);
-      }
+    protected override void OnClosing(CancelEventArgs e)
+    {
+      var finalState = twain.TryStepdown(STATE.S2);
+      Debug.WriteLine($"Stepdown result state={finalState}");
+
+      base.OnClosing(e);
     }
   }
 }
\ No newline at end of file
diff --git a/src/NTwain/Triplets/DATParent.cs b/src/NTwain/Triplets/DATParent.cs
index cd0a9d9..778817d 100644
--- a/src/NTwain/Triplets/DATParent.cs
+++ b/src/NTwain/Triplets/DATParent.cs
@@ -22,6 +22,7 @@ namespace NTwain.Triplets
       STS rc;
       if ((rc = DoIt(MSG.OPENDSM, ref hwnd)) == STS.SUCCESS)
       {
+        Session._hwnd = hwnd;
         Session.State = STATE.S3;
         // determine memory mgmt routines used
         if ((((DG)Session._appIdentityLegacy.SupportedGroups) & DG.DSM2) == DG.DSM2)
@@ -46,8 +47,9 @@ namespace NTwain.Triplets
       STS rc;
       if ((rc = DoIt(MSG.CLOSEDSM, ref hwnd)) == STS.SUCCESS)
       {
-        Session.State = STATE.S2;
+        Session._hwnd = IntPtr.Zero;
         Session._entryPoint = default;
+        Session.State = STATE.S2;
       }
       return rc;
     }
diff --git a/src/NTwain/TwainSession.cs b/src/NTwain/TwainSession.cs
index 5a2c877..1e1033e 100644
--- a/src/NTwain/TwainSession.cs
+++ b/src/NTwain/TwainSession.cs
@@ -6,7 +6,7 @@ using TWAINWorkingGroup;
 
 namespace NTwain
 {
-  // this file contains initialization-related things.
+  // this file contains initialization/cleanup things.
 
   public partial class TwainSession
   {
@@ -83,5 +83,22 @@ namespace NTwain
       DGImage = new DGImage(this);
       DGAudio = new DGAudio(this);
     }
+
+    internal IntPtr _hwnd;
+
+    /// <summary>
+    /// Tries to bring the TWAIN session down to some state.
+    /// </summary>
+    /// <param name="targetState"></param>
+    /// <returns>The final state.</returns>
+    public STATE TryStepdown(STATE targetState)
+    {
+      if (State > targetState)
+      {
+        // shouldn't care about handle when closing really
+        DGControl.Parent.CloseDSM(ref _hwnd);
+      }
+      return State;
+    }
   }
 }