diff --git a/daemon.py b/daemon.py
index 81b664b01..03c9300f2 100644
--- a/daemon.py
+++ b/daemon.py
@@ -17,7 +17,6 @@ from socket import error as SocketError
 import errno
 from functools import partial
 import pyqrcode
-import idna
 # for saving images
 from hashlib import sha256
 from hashlib import sha1
@@ -184,6 +183,7 @@ from shares import addShare
 from shares import removeShare
 from shares import expireShares
 from categories import setHashtagCategory
+from utils import decodedHost
 from utils import isPublicPost
 from utils import getLockedAccount
 from utils import hasUsersPath
@@ -9876,11 +9876,7 @@ class PubServer(BaseHTTPRequestHandler):
     def do_GET(self):
         callingDomain = self.server.domainFull
         if self.headers.get('Host'):
-            # IDNA decoding is an idempotent operation so this
-            # should not break 'normal' domains.
-            # For non-IDNA domains perhaps this behaviour should
-            # be disabled: TODO add config option?
-            callingDomain = idna.decode(self.headers['Host'])
+            callingDomain = decodedHost(self.headers['Host'])
             if self.server.onionDomain:
                 if callingDomain != self.server.domain and \
                    callingDomain != self.server.domainFull and \
@@ -12039,9 +12035,7 @@ class PubServer(BaseHTTPRequestHandler):
     def do_HEAD(self):
         callingDomain = self.server.domainFull
         if self.headers.get('Host'):
-            # As in the GET handler this should be idempotent but
-            # for security maybe make configurable.
-            callingDomain = idna.decode(self.headers['Host'])
+            callingDomain = decodedHost(self.headers['Host'])
             if self.server.onionDomain:
                 if callingDomain != self.server.domain and \
                    callingDomain != self.server.domainFull and \
@@ -12992,9 +12986,7 @@ class PubServer(BaseHTTPRequestHandler):
 
         callingDomain = self.server.domainFull
         if self.headers.get('Host'):
-            # As notes in the GET handler, this should be idempotent
-            # but should be configurable just in case
-            callingDomain = idna.decode(self.headers['Host'])
+            callingDomain = decodedHost(self.headers['Host'])
             if self.server.onionDomain:
                 if callingDomain != self.server.domain and \
                    callingDomain != self.server.domainFull and \
diff --git a/utils.py b/utils.py
index fe2deda4c..35d68de22 100644
--- a/utils.py
+++ b/utils.py
@@ -14,11 +14,36 @@ import json
 from socket import error as SocketError
 import errno
 import urllib.request
+import idna
 from pprint import pprint
 from calendar import monthrange
 from followingCalendar import addPersonToCalendar
 
 
+def _localNetworkHost(host: str) -> bool:
+    """Returns true if the given host is on the local network
+    """
+    if host.startswith('192.') or \
+       host.startswith('127.') or \
+       host.startswith('10.'):
+        return True
+    return False
+
+
+def decodedHost(host: str) -> str:
+    """Convert hostname to internationalized domain
+    https://en.wikipedia.org/wiki/Internationalized_domain_name
+    """
+    if ':' not in host:
+       if not _localNetworkHost(host):
+           if not host.endswith('.onion'):
+               if not host.endswith('.i2p'):
+                   # For domains on ports numbers don't use idna
+                   # eg. mydomain:8000
+                   return idna.decode(host)
+    return host
+
+
 def getLockedAccount(actorJson: {}) -> bool:
     """Returns whether the given account requires follower approval
     """