diff --git a/dopt.DeltaBarth.Tests/JsonStructsTest.cs b/dopt.DeltaBarth.Tests/JsonStructsTest.cs
index f98c930..8ae8451 100644
--- a/dopt.DeltaBarth.Tests/JsonStructsTest.cs
+++ b/dopt.DeltaBarth.Tests/JsonStructsTest.cs
@@ -42,7 +42,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.AreEqual("caused by test", parsed.message);
             Assert.IsNull(parsed.apiServerError);
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
         [TestMethod]
         public void Parse_ApiError_Test()
@@ -62,7 +62,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.IsNull(parsed.title);
             Assert.IsNull(parsed.traceId);
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
         [TestMethod]
         public void Parse_Credentials_Test()
@@ -79,7 +79,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.AreEqual("test1", parsed.database);
             Assert.AreEqual("mandant1", parsed.mandant);
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
         [TestMethod]
         public void Parse_SalesPrognosisResult_Test()
@@ -95,7 +95,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.AreEqual(12, parsed.monat);
             Assert.AreEqual(3000.3456m, parsed.vorhersage);
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
         [TestMethod]
         public void Parse_SalesPrognosisResults_Test()
@@ -118,7 +118,7 @@ namespace dopt.DeltaBarth.Tests
                 Assert.AreEqual(arr[i], parsed.daten[i]);
             }
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
         [TestMethod]
         public void Parse_SalesPrognosisExport_Test()
@@ -147,7 +147,7 @@ namespace dopt.DeltaBarth.Tests
                 Assert.AreEqual(data.daten[i], parsed.response.daten[i]);
             }
             PrettyPrint(parsed);
-            plugin.Shutdown();
+            plugin.Dispose();
         }
     }
 }
diff --git a/dopt.DeltaBarth.Tests/PluginTest.cs b/dopt.DeltaBarth.Tests/PluginTest.cs
index c361ead..5b9cc18 100644
--- a/dopt.DeltaBarth.Tests/PluginTest.cs
+++ b/dopt.DeltaBarth.Tests/PluginTest.cs
@@ -33,7 +33,7 @@ namespace dopt.DeltaBarth.Tests
             v = config["delta-barth-server:api:mandant"];
             Assert.IsNotNull(v);
             mandant = v;
-    }
+        }
     }
     public class TPlugin : DeltaBarth.Plugin
     {
@@ -62,7 +62,7 @@ namespace dopt.DeltaBarth.Tests
         public void ConstructInitialiseFinalise_Test()
         {
             var test = new TPlugin();
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void Set_and_Obtain_Credentials_Test()
@@ -76,7 +76,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.AreEqual(password, creds.password);
             Assert.AreEqual(database, creds.database);
             Assert.AreEqual(mandant, creds.mandant);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void Set_and_Obtain_BaseApiUrl_Test()
@@ -87,7 +87,7 @@ namespace dopt.DeltaBarth.Tests
             var apiUrlGet = test.GetBaseApiUrl();
             Console.WriteLine($"Result from Python session was: {apiUrlGet}");
             Assert.AreEqual(apiUrlSet, apiUrlGet);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void Startup_Test()
@@ -104,7 +104,7 @@ namespace dopt.DeltaBarth.Tests
             Assert.AreEqual(password, creds.password);
             Assert.AreEqual(database, creds.database);
             Assert.AreEqual(mandant, creds.mandant);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void UmsatzprognoseDummy_WithoutParams_Test()
@@ -114,7 +114,7 @@ namespace dopt.DeltaBarth.Tests
             test.Startup(apiUrlSet, user, password, database, mandant);
             var res = test.UmsatzprognoseDummy(null, null);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void UmsatzprognoseDummy_WithCompanyIdWithoutDate_Test()
@@ -125,7 +125,7 @@ namespace dopt.DeltaBarth.Tests
             var comp_id = 1000;
             var res = test.UmsatzprognoseDummy(comp_id, null);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         public void UmsatzprognoseDummy_WithoutCompanyIdWithDate_Test()
@@ -136,7 +136,7 @@ namespace dopt.DeltaBarth.Tests
             var date = new DateTime(2023, 1, 1, 12, 45, 30);
             var res = test.UmsatzprognoseDummy(null, date);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
         
         [TestMethod]
@@ -149,7 +149,7 @@ namespace dopt.DeltaBarth.Tests
             var comp_id = 1024;
             var res = test.Umsatzprognose(comp_id, null);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         [TestCategory("ActiveAPI")]
@@ -161,7 +161,7 @@ namespace dopt.DeltaBarth.Tests
             var date = new DateTime(2030, 1, 1, 12, 45, 30);
             var res = test.Umsatzprognose(null, date);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
         [TestMethod]
         [TestCategory("ActiveAPI")]
@@ -173,7 +173,7 @@ namespace dopt.DeltaBarth.Tests
             var date = new DateTime(2015, 1, 1, 12, 45, 30);
             var res = test.Umsatzprognose(null, date);
             PrettyPrint(res);
-            test.Shutdown();
+            test.Dispose();
         }
     }
 }
diff --git a/dopt.DeltaBarth/Plugin.cs b/dopt.DeltaBarth/Plugin.cs
index 20fa8f2..ebb9b4d 100644
--- a/dopt.DeltaBarth/Plugin.cs
+++ b/dopt.DeltaBarth/Plugin.cs
@@ -18,25 +18,25 @@ namespace dopt.DeltaBarth
         }
         public void Startup(string basisApiUrl, string nutzername, string passwort, string datenbank, string mandant)
         {
+            AssertNotDisposed();
             SetzeBasisApiUrl(basisApiUrl);
             SetzeNutzerdaten(nutzername, passwort, datenbank, mandant);
         }
-        public void Shutdown()
-        {
-            base.Finalise();
-        }
         public void SetzeBasisApiUrl(string basisApiUrl)
         {
+            AssertNotDisposed();
             pyModManagement.set_base_url(basisApiUrl);
         }
         public void SetzeNutzerdaten(string nutzername, string passwort, string datenbank, string mandant)
         {
+            AssertNotDisposed();
             using (Py.GIL()) {
                 pyModManagement.set_credentials(nutzername, passwort, datenbank, mandant);
             }
         }
         public JsonStructs.UmsatzPrognoseAusgabe UmsatzprognoseDummy(int? firmaId, DateTime? buchungsDatum)
         {
+            AssertNotDisposed();
             string pyJson;
             using (Py.GIL())
             {
@@ -48,6 +48,7 @@ namespace dopt.DeltaBarth
         }
         public JsonStructs.UmsatzPrognoseAusgabe Umsatzprognose(int? firmaId, DateTime? buchungsDatum)
         {
+            AssertNotDisposed();
             string pyJson;
             using (Py.GIL())
             {
@@ -59,6 +60,7 @@ namespace dopt.DeltaBarth
         }
         protected string GetBaseApiUrl()
         {
+            AssertNotDisposed();
             string pyJson;
             using (Py.GIL())
             {
@@ -68,6 +70,7 @@ namespace dopt.DeltaBarth
         }
         protected JsonStructs.Credentials GetCredentials()
         {
+            AssertNotDisposed();
             string pyJson;
             using (Py.GIL())
             {
diff --git a/dopt.DeltaBarth/dopt.DeltaBarth.csproj b/dopt.DeltaBarth/dopt.DeltaBarth.csproj
index ade9666..2eaa8c7 100644
--- a/dopt.DeltaBarth/dopt.DeltaBarth.csproj
+++ b/dopt.DeltaBarth/dopt.DeltaBarth.csproj
@@ -10,7 +10,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="dopt.SharpPython" Version="0.2.1" />
+    <PackageReference Include="dopt.SharpPython" Version="0.3.0" />
 	<Content Include="..\python\**\*">
 		<Link>python\%(RecursiveDir)/%(FileName)%(Extension)</Link>
 		<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>