diff --git a/src/callbacks.py b/src/callbacks.py
index 06371b352..a021f13ec 100644
--- a/src/callbacks.py
+++ b/src/callbacks.py
@@ -925,9 +925,8 @@ class NestedCommandsIrcProxy(ReplyIrcProxy):
                         log.warning('Truncating to %s bytes from %s bytes.',
                                     maximumLength, len(s))
                         s = s[:maximumLength]
-                    s_too_long = len(s.encode()) < allowedLength \
-                            if minisix.PY3 else len(s) < allowedLength
-                    if s_too_long or \
+                    s_size = len(s.encode()) if minisix.PY3 else len(s)
+                    if s_size > allowedLength or \
                        not conf.get(conf.supybot.reply.mores, target):
                         # In case we're truncating, we add 20 to allowedLength,
                         # because our allowedLength is shortened for the
diff --git a/src/ircutils.py b/src/ircutils.py
index 8299eb93f..ccda3392d 100644
--- a/src/ircutils.py
+++ b/src/ircutils.py
@@ -598,10 +598,7 @@ class FormatParser(object):
 
 def wrap(s, length, break_on_hyphens = False, break_long_words = False):
     processed = []
-    wrapper = textwrap.TextWrapper(width=length)
-    wrapper.break_long_words = break_long_words
-    wrapper.break_on_hyphens = break_on_hyphens
-    chunks = wrapper.wrap(s)
+    chunks = utils.str.byteTextWrap(s, length)
     context = None
     for chunk in chunks:
         if context is not None:
diff --git a/src/utils/str.py b/src/utils/str.py
index a110c1b3b..b2670cb18 100644
--- a/src/utils/str.py
+++ b/src/utils/str.py
@@ -34,6 +34,7 @@ Simple utility functions related to strings.
 """
 
 import re
+import sys
 import time
 import string
 import textwrap
@@ -305,6 +306,25 @@ def perlVariableSubstitute(vars, text):
                 return '$' + unbraced
     return _perlVarSubstituteRe.sub(replacer, text)
 
+def byteTextWrap(text, size):
+    """Similar to textwrap.wrap(), but considers the size of strings (in bytes)
+    instead of their length (in characters)."""
+    words = textwrap.TextWrapper()._split_chunks(text)
+    words.reverse() # use it as a stack
+    if sys.version_info[0] >= 3:
+        words = [w.encode() for w in words]
+    lines = [b'']
+    while words:
+        word = words.pop(-1)
+        if len(lines[-1]) + len(word) <= size:
+            lines[-1] += word
+        else:
+            lines.append(word)
+    if sys.version_info[0] >= 3:
+        return [l.decode() for l in lines]
+    else:
+        return lines
+
 def commaAndify(seq, comma=',', And=None):
     """Given a a sequence, returns an English clause for that sequence.
 
diff --git a/test/test_ircutils.py b/test/test_ircutils.py
index 41f6fe4dd..f7e573ab7 100644
--- a/test/test_ircutils.py
+++ b/test/test_ircutils.py
@@ -168,6 +168,34 @@ class FunctionsTestCase(SupyTestCase):
         s = ircutils.mircColor('[', 'blue') + ircutils.bold('09:21')
         self.assertEqual(ircutils.stripFormatting(s), '[09:21')
 
+    def testWrap(self):
+        if sys.version_info[0] < 3:
+            pred = len
+        else:
+            pred = lambda s:len(s.encode())
+
+        s = ('foo bar baz qux ' * 100)[0:-1]
+
+        r = ircutils.wrap(s, 10)
+        self.assertTrue(max(map(pred, r)) <= 10)
+        self.assertEqual(''.join(r), s)
+
+        r = ircutils.wrap(s, 100)
+        self.assertTrue(max(map(pred, r)) <= 100)
+        self.assertEqual(''.join(r), s)
+
+        s = (''.join([chr(0x1f527), chr(0x1f527), chr(0x1f527), ' ']) * 100)\
+                [0:-1]
+
+        r = ircutils.wrap(s, 20)
+        self.assertTrue(max(map(pred, r)) <= 20, (max(map(pred, r)), repr(r)))
+        self.assertEqual(''.join(r), s)
+
+        r = ircutils.wrap(s, 100)
+        self.assertTrue(max(map(pred, r)) <= 100)
+        self.assertEqual(''.join(r), s)
+
+
     def testSafeArgument(self):
         s = 'I have been running for 9 seconds'
         bolds = ircutils.bold(s)