diff --git a/tests/test_html_for_tweet.py b/tests/test_html_for_tweet.py
index 7331fa4..921dfee 100644
--- a/tests/test_html_for_tweet.py
+++ b/tests/test_html_for_tweet.py
@@ -89,6 +89,19 @@ class TestHtmlForTweetTestCase(unittest.TestCase):
         self.assertEqual(tweet_text,
             'Say more about what\'s happening! Rolling out now: photos, videos, GIFs, polls, and Quote Tweets no longer count toward your 140 characters.<span class="twython-tweet-suffix"> <a href="https://t.co/I9pUC0NdZC" class="twython-media">pic.twitter.com/I9pUC0NdZC</a></span>')
 
+    def test_entities_with_prefix(self):
+        """
+        If there is a username mention at the start of a tweet it's in the
+        "prefix" and so isn't part of the main tweet display text.
+        But its length is still counted in the indices of any subsequent
+        mentions, urls, hashtags, etc.
+        """
+        self.maxDiff = 2200
+        tweet_object = self.load_tweet('entities_with_prefix')
+        tweet_text = self.api.html_for_tweet(tweet_object)
+        self.assertEqual(tweet_text,
+            u'<span class="twython-tweet-prefix"><a href="https://twitter.com/philgyford" class="twython-mention">@philgyford</a> </span>This is a test for <a href="https://twitter.com/visionphil" class="twython-mention">@visionphil</a> that includes a link <a href="https://t.co/sKw4J3A8SZ" class="twython-url">example.org</a> and <a href="https://twitter.com/search?q=%23hashtag" class="twython-hashtag">#hashtag</a> and X for good measure AND that is longer than 140 characters. <a href="https://t.co/jnQdy7Zg7u" class="twython-url">example.com</a>')
+
     def test_media(self):
         tweet_object = self.load_tweet('media')
         tweet_text = self.api.html_for_tweet(tweet_object)
diff --git a/tests/tweets/entities_with_prefix.json b/tests/tweets/entities_with_prefix.json
new file mode 100644
index 0000000..8ba8975
--- /dev/null
+++ b/tests/tweets/entities_with_prefix.json
@@ -0,0 +1,68 @@
+{  
+  "created_at":"Sat Jan 06 18:56:35 +0000 2018",
+  "id":949716340755091458,
+  "id_str":"949716340755091458",
+  "full_text":"@philgyford This is a test for @visionphil that includes a link https://t.co/sKw4J3A8SZ and #hashtag and X for good measure AND that is longer than 140 characters. https://t.co/jnQdy7Zg7u",
+  "truncated":false,
+  "display_text_range":[ 12, 187 ],
+  "entities":{  
+    "hashtags":[  
+      {  
+        "text":"hashtag",
+        "indices":[ 92, 100 ]
+      }
+    ],
+    "symbols":[  ],
+    "user_mentions":[  
+      {  
+        "screen_name":"philgyford",
+        "name":"Phil Gyford",
+        "id":12552,
+        "id_str":"12552",
+        "indices":[ 0, 11 ]
+      },
+      {  
+        "screen_name":"visionphil",
+        "name":"Vision Phil",
+        "id":104456050,
+        "id_str":"104456050",
+        "indices":[ 31, 42 ]
+      }
+    ],
+    "urls":[  
+      {  
+        "url":"https://t.co/sKw4J3A8SZ",
+        "expanded_url":"http://example.org",
+        "display_url":"example.org",
+        "indices":[ 64, 87 ]
+      },
+      {  
+        "url":"https://t.co/jnQdy7Zg7u",
+        "expanded_url":"http://example.com",
+        "display_url":"example.com",
+        "indices":[ 164, 187 ]
+      }
+    ]
+  },
+  "source":"<a href=\"http://tapbots.com/software/tweetbot/mac\" rel=\"nofollow\">Tweetbot for Mac</a>",
+  "in_reply_to_status_id":948561036889722880,
+  "in_reply_to_status_id_str":"948561036889722880",
+  "in_reply_to_user_id":12552,
+  "in_reply_to_user_id_str":"12552",
+  "in_reply_to_screen_name":"philgyford",
+  "user":{  
+    "id":2030131,
+    "id_str":"2030131"
+  },
+  "geo":null,
+  "coordinates":null,
+  "place":null,
+  "contributors":null,
+  "is_quote_status":false,
+  "retweet_count":0,
+  "favorite_count":0,
+  "favorited":false,
+  "retweeted":false,
+  "possibly_sensitive":false,
+  "lang":"en"
+}
diff --git a/twython/api.py b/twython/api.py
index f25cc97..57a10a6 100644
--- a/twython/api.py
+++ b/twython/api.py
@@ -581,6 +581,8 @@ class Twython(EndpointsMixin, object):
 
                     if display_text_start <= temp['start'] <= display_text_end:
                         temp['replacement'] = mention_html
+                        temp['start'] -= display_text_start
+                        temp['end'] -= display_text_start
                         entities.append(temp)
                     else:
                         # Make the '@username' at the start, before
@@ -592,8 +594,8 @@ class Twython(EndpointsMixin, object):
             if 'hashtags' in tweet['entities']:
                 for entity in tweet['entities']['hashtags']:
                     temp = {}
-                    temp['start'] = entity['indices'][0]
-                    temp['end'] = entity['indices'][1]
+                    temp['start'] = entity['indices'][0] - display_text_start
+                    temp['end'] = entity['indices'][1] - display_text_start
 
                     url_html = '<a href="https://twitter.com/search?q=%%23%(hashtag)s" class="twython-hashtag">#%(hashtag)s</a>' % {'hashtag': entity['text']}
 
@@ -604,8 +606,8 @@ class Twython(EndpointsMixin, object):
             if 'symbols' in tweet['entities']:
                 for entity in tweet['entities']['symbols']:
                     temp = {}
-                    temp['start'] = entity['indices'][0]
-                    temp['end'] = entity['indices'][1]
+                    temp['start'] = entity['indices'][0] - display_text_start
+                    temp['end'] = entity['indices'][1] - display_text_start
 
                     url_html = '<a href="https://twitter.com/search?q=%%24%(symbol)s" class="twython-symbol">$%(symbol)s</a>' % {'symbol': entity['text']}
 
@@ -616,8 +618,8 @@ class Twython(EndpointsMixin, object):
             if 'urls' in tweet['entities']:
                 for entity in tweet['entities']['urls']:
                     temp = {}
-                    temp['start'] = entity['indices'][0]
-                    temp['end'] = entity['indices'][1]
+                    temp['start'] = entity['indices'][0] - display_text_start
+                    temp['end'] = entity['indices'][1] - display_text_start
 
                     if use_display_url and entity.get('display_url') and not use_expanded_url:
                         shown_url = entity['display_url']