diff --git a/IPython/nbconvert/filters/ansi.py b/IPython/nbconvert/filters/ansi.py
index 0206425..3177bd2 100644
--- a/IPython/nbconvert/filters/ansi.py
+++ b/IPython/nbconvert/filters/ansi.py
@@ -36,7 +36,7 @@ def remove_ansi(source):
         Source to remove the ansi from
     """
     
-    return re.sub(r'\033\[(\d|:)+?m', '', source)
+    return re.sub(r'\033\[(\d|;)+?m', '', source)
 
 
 def ansi2html(text):