diff --git a/NETGenerator/Helpers.cs b/NETGenerator/Helpers.cs
index f7d62924a..0ad5c0fdc 100644
--- a/NETGenerator/Helpers.cs
+++ b/NETGenerator/Helpers.cs
@@ -838,7 +838,7 @@ namespace PascalABCCompiler.NETGenerator {
 
         public bool IsConstructedGenericType(Type t)
         {
-            if (t is TypeBuilder || t is GenericTypeParameterBuilder || t is EnumBuilder)
+            if (t is TypeBuilder || t is GenericTypeParameterBuilder || t is EnumBuilder || t.GetType().FullName == "System.Reflection.Emit.TypeBuilderInstantiation")
                 return true;
             if (t.IsGenericType)
                 foreach (Type gt in t.GetGenericArguments())
diff --git a/TestSuite/foreach10.pas b/TestSuite/foreach10.pas
new file mode 100644
index 000000000..13bca3c12
--- /dev/null
+++ b/TestSuite/foreach10.pas
@@ -0,0 +1,15 @@
+type
+  // Обязательно пользовательский шаблонный тип
+  t1<T> = class end;
+  
+begin
+  // Обязательно массив
+  // foreach по "a.AsEnumerable" не падает
+  var a: array of t1<byte> := Arr(new t1<byte>);
+  var i := 0;     
+  foreach var x in a do
+    begin
+      Inc(i);
+    end;
+  assert(i = 1);
+end.
\ No newline at end of file