diff --git a/test/ThriftTest.thrift b/test/ThriftTest.thrift
index 414f9a54..a58ed97 100644
--- a/test/ThriftTest.thrift
+++ b/test/ThriftTest.thrift
@@ -105,12 +105,13 @@
 {
   1: map<Numberz, UserId> userMap,
   2: list<Xtruct> xtructs
-}
+} (python.immutable= "")
 
 struct CrazyNesting {
   1: string string_field,
   2: optional set<Insanity> set_field,
-  3: required list< map<set<i32>,map<i32,set<list<map<Insanity,string>>>>>> list_field,
+  3: required list<map<set<i32> (python.immutable = ""),
+                       map<i32,set<list<map<Insanity,string>(python.immutable = "")> (python.immutable = "")>>>> list_field,
   4: binary binary_field
 }