diff --git a/tool/test/org/antlr/v4/test/runtime/csharp/CSharp.test.stg b/tool/test/org/antlr/v4/test/runtime/csharp/CSharp.test.stg
index b1cf1c39e..239a24716 100644
--- a/tool/test/org/antlr/v4/test/runtime/csharp/CSharp.test.stg
+++ b/tool/test/org/antlr/v4/test/runtime/csharp/CSharp.test.stg
@@ -168,6 +168,8 @@ Concat(a,b) ::= "<a><b>"
 
 DeclareLocal(s,v) ::= "Object <s> = <v>;"
 
+AssertIsList(v) ::= "System.Collections.IList __ttt__ = <v>;" // just use static type system
+
 AssignLocal(s,v) ::= "<s> = <v>;"
 
 InitIntMember(n,v) ::= <%int <n> = <v>;%>