diff --git a/test/functional/timing.json b/test/functional/timing.json
index 6a24e11b25..d110423498 100644
--- a/test/functional/timing.json
+++ b/test/functional/timing.json
@@ -1,366 +1,370 @@
 [
  {
   "name": "abandonconflict.py",
-  "time": 11
+  "time": 18
  },
  {
   "name": "abc-checkdatasig-activation.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "abc-cmdline.py",
-  "time": 7
+  "time": 8
  },
  {
   "name": "abc-finalize-block.py",
-  "time": 5
+  "time": 7
  },
  {
   "name": "abc-high_priority_transaction.py",
-  "time": 6
+  "time": 16
  },
  {
   "name": "abc-magnetic-anomaly-activation.py",
-  "time": 5
+  "time": 8
  },
  {
   "name": "abc-magnetic-anomaly-mining.py",
-  "time": 3
+  "time": 19
  },
  {
   "name": "abc-mempool-accept-txn.py",
-  "time": 3
+  "time": 10
  },
  {
   "name": "abc-p2p-compactblocks.py",
-  "time": 253
+  "time": 743
  },
  {
   "name": "abc-p2p-fullblocktest.py",
-  "time": 31
+  "time": 125
  },
  {
   "name": "abc-parkedchain.py",
-  "time": 4
+  "time": 16
  },
  {
   "name": "abc-replay-protection.py",
-  "time": 3
+  "time": 6
  },
  {
   "name": "abc-rpc.py",
   "time": 2
  },
  {
   "name": "abc-sync-chain.py",
-  "time": 2
+  "time": 4
  },
  {
   "name": "abc-transaction-ordering.py",
-  "time": 5
+  "time": 8
  },
  {
   "name": "assumevalid.py",
-  "time": 8
+  "time": 66
  },
  {
   "name": "bip65-cltv-p2p.py",
-  "time": 4
+  "time": 17
  },
  {
   "name": "bip68-112-113-p2p.py",
-  "time": 14
+  "time": 28
  },
  {
   "name": "bip68-sequence.py",
-  "time": 12
+  "time": 22
  },
  {
   "name": "bipdersig-p2p.py",
-  "time": 3
+  "time": 46
  },
  {
   "name": "bitcoin_cli.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "blockchain.py",
-  "time": 10
+  "time": 11
  },
  {
   "name": "dbcrash.py",
   "time": 537
  },
  {
   "name": "decodescript.py",
   "time": 2
  },
  {
   "name": "disablewallet.py",
   "time": 2
  },
  {
   "name": "disconnect_ban.py",
   "time": 7
  },
  {
   "name": "example_test.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "fundrawtransaction.py",
-  "time": 31
+  "time": 42
  },
  {
   "name": "getblocktemplate_longpoll.py",
-  "time": 67
+  "time": 68
  },
  {
   "name": "getchaintips.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "httpbasics.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "import-rescan.py",
-  "time": 3
+  "time": 18
  },
  {
   "name": "importmulti.py",
-  "time": 5
+  "time": 16
  },
  {
   "name": "importprunedfunds.py",
-  "time": 2
+  "time": 5
  },
  {
   "name": "invalidateblock.py",
-  "time": 7
+  "time": 8
  },
  {
   "name": "invalidblockrequest.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "invalidtxrequest.py",
-  "time": 3
+  "time": 6
  },
  {
   "name": "keypool-topup.py",
-  "time": 8
+  "time": 18
  },
  {
   "name": "keypool.py",
-  "time": 6
+  "time": 9
  },
  {
   "name": "listsinceblock.py",
-  "time": 3
+  "time": 6
  },
  {
   "name": "listtransactions.py",
-  "time": 9
+  "time": 7
  },
  {
   "name": "maxuploadtarget.py",
-  "time": 21
+  "time": 29
  },
  {
   "name": "mempool_limit.py",
-  "time": 4
+  "time": 7
  },
  {
   "name": "mempool_packages.py",
-  "time": 9
+  "time": 70
  },
  {
   "name": "mempool_persist.py",
-  "time": 17
+  "time": 19
  },
  {
   "name": "mempool_reorg.py",
-  "time": 6
+  "time": 3
  },
  {
   "name": "mempool_resurrect_test.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "mempool_spendcoinbase.py",
   "time": 2
  },
  {
   "name": "merkle_blocks.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "minchainwork.py",
-  "time": 5
+  "time": 7
  },
  {
   "name": "mining.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "multi_rpc.py",
   "time": 4
  },
  {
   "name": "multiwallet.py",
-  "time": 5
+  "time": 9
  },
  {
   "name": "net.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "notifications.py",
-  "time": 5
+  "time": 7
  },
  {
   "name": "nulldummy.py",
-  "time": 2
+  "time": 6
  },
  {
   "name": "p2p-acceptblock.py",
-  "time": 4
+  "time": 45
  },
  {
   "name": "p2p-compactblocks.py",
-  "time": 12
+  "time": 21
  },
  {
   "name": "p2p-feefilter.py",
-  "time": 23
+  "time": 26
  },
  {
   "name": "p2p-fingerprint.py",
-  "time": 8
+  "time": 9
  },
  {
   "name": "p2p-fullblocktest.py",
-  "time": 97
+  "time": 189
  },
  {
   "name": "p2p-leaktests.py",
-  "time": 7
+  "time": 8
  },
  {
   "name": "p2p-mempool.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "p2p-timeouts.py",
-  "time": 64
+  "time": 65
  },
  {
   "name": "preciousblock.py",
-  "time": 3
+  "time": 4
  },
  {
   "name": "prioritise_transaction.py",
-  "time": 4
+  "time": 6
  },
  {
   "name": "proxy_test.py",
-  "time": 3
+  "time": 4
  },
  {
   "name": "pruning.py",
-  "time": 502
+  "time": 1039
  },
  {
   "name": "rawtransactions.py",
   "time": 16
  },
  {
   "name": "reindex.py",
-  "time": 12
+  "time": 13
  },
  {
   "name": "resendwallettransactions.py",
   "time": 5
  },
  {
   "name": "rest.py",
-  "time": 6
+  "time": 9
  },
  {
   "name": "rpcbind_test.py",
   "time": 24
  },
  {
   "name": "rpcnamedargs.py",
-  "time": 2
+  "time": 3
  },
  {
   "name": "sendheaders.py",
-  "time": 13
+  "time": 18
  },
  {
   "name": "signmessages.py",
   "time": 2
  },
  {
   "name": "signrawtransactions.py",
   "time": 2
  },
  {
   "name": "txn_clone.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "txn_clone.py --mineblock",
-  "time": 3
+  "time": 5
  },
  {
   "name": "txn_doublespend.py",
-  "time": 3
+  "time": 5
  },
  {
   "name": "txn_doublespend.py --mineblock",
-  "time": 3
+  "time": 5
+ },
+ {
+  "name": "uacomment.py",
+  "time": 6
  },
  {
   "name": "uptime.py",
   "time": 2
  },
  {
   "name": "wallet.py",
-  "time": 31
+  "time": 67
  },
  {
   "name": "wallet_accounts.py",
-  "time": 2
+  "time": 14
  },
  {
   "name": "wallet_dump.py",
-  "time": 5
+  "time": 8
  },
  {
   "name": "wallet_encryption.py",
-  "time": 7
+  "time": 9
  },
  {
   "name": "wallet_hd.py",
-  "time": 17
+  "time": 122
  },
  {
   "name": "wallet_receivedby.py",
-  "time": 12
+  "time": 9
  },
  {
   "name": "walletbackup.py",
-  "time": 100
+  "time": 147
  },
  {
   "name": "zapwallettxes.py",
-  "time": 10
+  "time": 12
  },
  {
   "name": "zmq_test.py",
-  "time": 11
+  "time": 7
  }
 ]
\ No newline at end of file
diff --git a/test/functional/uacomment.py b/test/functional/uacomment.py
new file mode 100755
index 0000000000..eda8e66965
--- /dev/null
+++ b/test/functional/uacomment.py
@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test the -uacomment option."""
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+
+class UacommentTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+        self.setup_clean_chain = True
+
+    def run_test(self):
+        self.log.info("test multiple -uacomment")
+        test_uacomment = self.nodes[0].getnetworkinfo()["subversion"]
+        subversion_len = len(test_uacomment)
+        assert_equal(test_uacomment[-12:-2], "testnode-0")
+
+        self.restart_node(0, ["-uacomment=foo"])
+        foo_uacomment = self.nodes[0].getnetworkinfo()["subversion"][-17:-2]
+        assert_equal(foo_uacomment, "testnode-0; foo")
+
+        self.log.info("test -uacomment max length")
+        self.stop_node(0)
+        expected = "Total length of network version string (290) exceeds maximum length (256). Reduce the number or size of uacomments."
+        self.assert_start_raises_init_error(
+            0, ["-uacomment=" + 'a' * 256], expected)
+
+        self.log.info("test -uacomment unsafe characters")
+        for unsafe_char in ['/', ':', '(', ')']:
+            expected = "User Agent comment (" + \
+                unsafe_char + ") contains unsafe characters"
+            self.assert_start_raises_init_error(
+                0, ["-uacomment=" + unsafe_char], expected)
+
+
+if __name__ == '__main__':
+    UacommentTest().main()