diff --git a/test/Int64Test.thrift b/test/Int64Test.thrift
index 7a9ed2f..348cc9c 100644
--- a/test/Int64Test.thrift
+++ b/test/Int64Test.thrift
@@ -32,3 +32,13 @@
 const i64 MIN_SIGNED_INT64 = -9223372036854775808
 
 const list<i64> INT64_LIST = [SMALL_INT64, MAX_JS_SAFE_INT64, MIN_JS_SAFE_INT64, MAX_JS_SAFE_PLUS_ONE_INT64, MIN_JS_SAFE_MINUS_ONE_INT64, MAX_SIGNED_INT64, MIN_SIGNED_INT64]
+
+const map<i64, i64> INT64_2_INT64_MAP = {
+    SMALL_INT64: SMALL_INT64,
+    MAX_JS_SAFE_INT64: MAX_JS_SAFE_INT64,
+    MIN_JS_SAFE_INT64: MIN_JS_SAFE_INT64,
+    MAX_JS_SAFE_PLUS_ONE_INT64: MAX_JS_SAFE_PLUS_ONE_INT64,
+    MIN_JS_SAFE_MINUS_ONE_INT64: MIN_JS_SAFE_MINUS_ONE_INT64,
+    MAX_SIGNED_INT64: MAX_SIGNED_INT64,
+    MIN_SIGNED_INT64: MIN_SIGNED_INT64
+    }