diff --git a/INSTALL b/INSTALL.rst
similarity index 100%
rename from INSTALL
rename to INSTALL.rst
diff --git a/UPGRADE b/UPGRADE.rst
similarity index 100%
rename from UPGRADE
rename to UPGRADE.rst
diff --git a/trac/mimeview/api.py b/trac/mimeview/api.py
index e17dbe6e00..f47c65ef88 100644
--- a/trac/mimeview/api.py
+++ b/trac/mimeview/api.py
@@ -649,7 +649,7 @@ class Mimeview(Component):
         """)
 
     mime_map_patterns = ListOption('mimeviewer', 'mime_map_patterns',
-        'text/plain:README|INSTALL|COPYING.*',
+        'text/plain:README|INSTALL(?!\.rst)|COPYING.*',
         doc="""List of additional MIME types associated to filename patterns.
         Mappings are comma-separated, and each mapping consists of a MIME type
         and a Python regexp used for matching filenames, separated by a colon