diff --git a/ietf/meeting/urls.py b/ietf/meeting/urls.py
index 5da24ddb6f..18b123b4d8 100644
--- a/ietf/meeting/urls.py
+++ b/ietf/meeting/urls.py
@@ -64,7 +64,7 @@ def get_redirect_url(self, *args, **kwargs):
 type_interim_patterns = [
     url(r'^agenda/(?P<acronym>[A-Za-z0-9-]+)-drafts.pdf$', views.session_draft_pdf),
     url(r'^agenda/(?P<acronym>[A-Za-z0-9-]+)-drafts.tgz$', views.session_draft_tarfile),
-    url(r'^materials/%(document)s(?P<ext>\.[a-z0-9]+)$' % settings.URL_REGEXPS, views.materials_document),
+    url(r'^materials/%(document)s(?P<ext>\.[A-Za-z0-9]+)$' % settings.URL_REGEXPS, views.materials_document),
     url(r'^materials/%(document)s/?$' % settings.URL_REGEXPS, views.materials_document),
     url(r'^agenda.json$', views.agenda_json)
 ]
@@ -85,7 +85,7 @@ def get_redirect_url(self, *args, **kwargs):
     url(r'^week-view(?:.html)?/?$', AgendaRedirectView.as_view(pattern_name='agenda', permanent=True)),
     url(r'^materials(?:.html)?/?$', views.materials),
     url(r'^request_minutes/?$', views.request_minutes),
-    url(r'^materials/%(document)s(?P<ext>\.[a-z0-9]+)?/?$' % settings.URL_REGEXPS, views.materials_document),
+    url(r'^materials/%(document)s(?P<ext>\.[A-Za-z0-9]+)?/?$' % settings.URL_REGEXPS, views.materials_document),
     url(r'^session/?$', views.materials_editable_groups),
     url(r'^proceedings(?:.html)?/?$', views.proceedings),
     url(r'^proceedings(?:.html)?/finalize/?$', views.finalize_proceedings),