diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1777,7 +1777,7 @@ def import_(ui, repo, patch1, *patches, 
             if user:
                 ui.debug('From: %s\n' % user)
             diffs_seen = 0
-            ok_types = ('application/x-patch', 'text/plain', 'text/x-patch')
+            ok_types = ('text/plain', 'text/x-diff', 'text/x-patch')
             for part in msg.walk():
                 content_type = part.get_content_type()
                 ui.debug('Content-Type: %s\n' % content_type)