diff --git a/tests/webtbs/tw39581.pp b/tests/webtbs/tw39581.pp
new file mode 100644
index 0000000000..2e263e21cb
--- /dev/null
+++ b/tests/webtbs/tw39581.pp
@@ -0,0 +1,35 @@
+{ %NORUN }
+
+program tw39581;
+
+{$Mode Delphi} {$H+}
+
+Type
+  TImplClass<P> = class;
+
+  iLinkingIntf<P> = interface
+    procedure NestedCall(const DataFrom: TImplClass<P>);
+  end;
+
+(* Компиляция проекта, цель: Project1.exe: Код завершения 1, ошибок: 1
+Project1.pas(9,55) Error: Internal error 2012101001
+*)
+
+  { TImplClass }
+
+  TImplClass<P> = class( TInterfacedObject, iLinkingIntf<P> )
+  protected
+    procedure NestedCall(const DataFrom: TImplClass<P> );
+  end;
+
+{ TImplClass }
+
+procedure TImplClass<P>.NestedCall(const DataFrom: TImplClass<P>);
+begin
+
+end;
+
+
+begin
+end.
+