diff --git a/test/msg-v2/validate.test.js b/test/msg-v2/validate.test.js
index c1f3857..f24e10c 100644
--- a/test/msg-v2/validate.test.js
+++ b/test/msg-v2/validate.test.js
@@ -1,5 +1,4 @@
 const tape = require('tape')
-const base58 = require('bs58')
 const MsgV2 = require('../../lib/msg-v2')
 const { generateKeypair } = require('../util')
 
@@ -18,6 +17,43 @@ tape('validate root msg', (t) => {
   t.end()
 })
 
+tape('validate group tangle', (t) => {
+  const pubkeys = new Set()
+  const keys1 = generateKeypair('alice')
+  pubkeys.add(keys1.id)
+
+  const groupMsg0 = MsgV2.createGroup(keys1, 'alice')
+  const group = MsgV2.getMsgHash(groupMsg0)
+  const groupMsg0Hash = group
+
+  const tangle = new MsgV2.Tangle(group)
+
+  let err = MsgV2.validate(groupMsg0, tangle, pubkeys, groupMsg0Hash, group)
+  if (err) console.log(err)
+  t.error(err, 'valid group root msg')
+
+  tangle.add(group, groupMsg0)
+
+  const keys2 = generateKeypair('bob')
+
+  const groupMsg1 = MsgV2.create({
+    group: null,
+    groupTips: null,
+    type: 'group',
+    data: { add: keys2.id },
+    tangles: {
+      [group]: tangle,
+    },
+    keys: keys1, // announcing keys2 but signing with keys1
+  })
+  const groupMsg1Hash = MsgV2.getMsgHash(groupMsg1)
+
+  err = MsgV2.validate(groupMsg1, tangle, pubkeys, groupMsg1Hash, group)
+  if (err) console.log(err)
+  t.error(err, 'valid group msg')
+  t.end()
+})
+
 tape('validate 2nd msg with existing root', (t) => {
   const keys = generateKeypair('alice')
   const group = MsgV2.getMsgHash(MsgV2.createGroup(keys, 'alice'))