diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 4d136285d2..10600bd265 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -1553,6 +1553,9 @@ def check_message(sender, client, addressee,
     message_content = message_content_raw.rstrip()
     if len(message_content) == 0:
         raise JsonableError(_("Message must not be empty"))
+    if '\x00' in message_content:
+        raise JsonableError(_("Message must not contain null bytes"))
+
     message_content = truncate_body(message_content)
 
     if realm is None:
@@ -1652,6 +1655,7 @@ def _internal_prep_message(realm, sender, addressee, content):
     messages together as one database query.
     Call do_send_messages with a list of the return values of this method.
     """
+    # Remove any null bytes from the content
     if len(content) > MAX_MESSAGE_LENGTH:
         content = content[0:3900] + "\n\n[message was too long and has been truncated]"
 
diff --git a/zerver/tests/test_messages.py b/zerver/tests/test_messages.py
index c085816918..62551d479a 100644
--- a/zerver/tests/test_messages.py
+++ b/zerver/tests/test_messages.py
@@ -1085,11 +1085,21 @@ class MessagePOSTTest(ZulipTestCase):
         self.assertEqual(ujson.loads(result1.content)['id'],
                          ujson.loads(result2.content)['id'])
 
+    def test_message_with_null_bytes(self):
+        # type: () -> None
+        """
+        A message with null bytes in it is handled.
+        """
+        self.login(self.example_email("hamlet"))
+        post_data = {"type": "stream", "to": "Verona", "client": "test suite",
+                     "content": u"  I like null bytes \x00 in my content", "subject": "Test subject"}
+        result = self.client_post("/json/messages", post_data)
+        self.assert_json_error(result, "Message must not contain null bytes")
+
     def test_strip_message(self):
         # type: () -> None
         """
-        Sending a message longer than the maximum message length succeeds but is
-        truncated.
+        A message with mixed whitespace at the end is cleaned up.
         """
         self.login(self.example_email("hamlet"))
         post_data = {"type": "stream", "to": "Verona", "client": "test suite",