diff --git a/TODO b/TODO
index 1791d17..5136a41 100644
--- a/TODO
+++ b/TODO
@@ -16,3 +16,4 @@ bugs:
 
 * "ValueError: list.remove(x): x not in list" when trying to close a tab (error recurred after adding conversation support).  Tabs can be reordered, then closed, as a workaround.
 * Links must be right-clicked on to activate - can't left-click on the link directly.  This seems to be a pygtk issue
+* Sometimes tweets are posted when we display 'failed to post tweet'... need to differentiate between kinds of errors... or something.
diff --git a/twitterwidgets.py b/twitterwidgets.py
index 37e21fd..521fab1 100644
--- a/twitterwidgets.py
+++ b/twitterwidgets.py
@@ -455,7 +455,7 @@ class TweetBox(gtk.HBox):
         new_text = re.sub(r'&([^;]*?)( |$)', r'&\1\2', new_text)
         new_text = re.sub(r'"([^;]*?)( |$)', r'"\1\2', new_text)
         if gtk.gtk_version[0] > 2 or (gtk.gtk_version[0] == 2 and gtk.gtk_version[1] >= 18):
-            new_text = re.sub(r"(http://.*?)([^0-9a-zA-Z.~/]|$)", r'<a href="\1">\1</a>\2', new_text)
+            new_text = re.sub(r"(http://.*?)([^0-9a-zA-Z.~/-_]|$)", r'<a href="\1">\1</a>\2', new_text)
             new_text = re.sub(r'@(.*?)([^0-9a-zA-Z_]|$)', self._make_user_link, new_text)
         self.text.set_markup(new_text)