diff --git a/src/Exceptions.cs b/src/Exceptions.cs
index 271219f..54cca04 100644
--- a/src/Exceptions.cs
+++ b/src/Exceptions.cs
@@ -2,11 +2,14 @@
 
 namespace DCFApixels.DragonECS
 {
-    public static class EcsThrowHalper_ClassicThreads
+    namespace ClassicThreadsInternal
     {
-        internal static void DoubleParallelIteration(this EcsThrowHalper _)
+        internal static class Throw
         {
-            throw new InvalidOperationException("It is forbidden to start a parallel iteration before the last one is finished.");
+            internal static void DoubleParallelIteration()
+            {
+                throw new InvalidOperationException("It is forbidden to start a parallel iteration before the last one is finished.");
+            }
         }
     }
 }
diff --git a/src/ThreadRunner.cs b/src/ThreadRunner.cs
index 7c23c5c..b4c338f 100644
--- a/src/ThreadRunner.cs
+++ b/src/ThreadRunner.cs
@@ -1,7 +1,7 @@
+using DCFApixels.DragonECS.ClassicThreadsInternal;
 using System;
 using System.Collections.Generic;
 using System.Threading;
-using static DCFApixels.DragonECS.EcsThrowHalper;
 
 namespace DCFApixels.DragonECS
 {