diff --git a/pelican/contents.py b/pelican/contents.py
index dbc33716..62406904 100644
--- a/pelican/contents.py
+++ b/pelican/contents.py
@@ -190,7 +190,7 @@ class Content(object):
         instrasite_link_regex = self.settings['INTRASITE_LINK_REGEX']
         regex = r"""
             (?P<markup><\s*[^\>]*  # match tag with src and href attr
-                (?:href|src)\s*=)
+                (?:href|src|poster)\s*=)
 
             (?P<quote>["\'])      # require value to be quoted
             (?P<path>{0}(?P<value>.*?))  # the url value