diff --git a/CIP-0034/registry.json b/CIP-0034/registry.json
index b7c2066c3f..e3b021d9c8 100644
--- a/CIP-0034/registry.json
+++ b/CIP-0034/registry.json
@@ -1,13 +1,13 @@
 {
     "PreProduction": {
         "Name": "Pre-Production",
-        "NetworkId": 3,
+        "NetworkId": 0,
         "NetworkMagic": 1,
         "GenesisHash": "d4b8de7a11d929a323373cbab6c1a9bdc931beffff11db111cf9d57356ee1937"
     },
     "Preview": {
         "Name": "Preview",
-        "NetworkId": 2,
+        "NetworkId": 0,
         "NetworkMagic": 2,
         "GenesisHash": "72593f260b66f26bef4fc50b38a8f24d3d3633ad2e854eaf73039eb9402706f1"
     },
@@ -16,5 +16,11 @@
         "NetworkId": 1,
         "NetworkMagic": 764824073,
         "GenesisHash": "5f20df933584822601f9e3f8c024eb5eb252fe8cefb24d1317dc3d432e940ebb"
+    },
+    "LegacyTestnet": {
+        "Name": "Legacy Testnet",
+        "NetworkId": 0,
+        "NetworkMagic": 1097911063,
+        "GenesisHash": "96fceff972c2c06bd3bb5243c39215333be6d56aaf4823073dca31afe5038471"
     }
-}
\ No newline at end of file
+}