--- a/hgext/largefiles/overrides.py	Mon Jun 19 16:08:20 2017 -0700
+++ b/hgext/largefiles/overrides.py	Tue Jun 20 16:33:46 2017 -0400
@@ -1007,7 +1007,8 @@
     archiver.done()
 
 def hgsubrepoarchive(orig, repo, archiver, prefix, match=None, decode=True):
-    if not repo._repo.lfstatus:
+    lfenabled = util.safehasattr(repo._repo, '_largefilesenabled')
+    if not lfenabled or not repo._repo.lfstatus:
         return orig(repo, archiver, prefix, match, decode)
 
     repo._get(repo._state + ('hg',))

--- a/tests/test-largefiles-misc.t	Mon Jun 19 16:08:20 2017 -0700
+++ b/tests/test-largefiles-misc.t	Tue Jun 20 16:33:46 2017 -0400
@@ -1075,6 +1075,10 @@
   $ hg -R subrepo-root status -S
   M large
   M no-largefiles/normal1
+  $ hg -R subrepo-root extdiff -p echo -S --config extensions.extdiff=
+  "*\\no-largefiles\\normal1" "*\\no-largefiles\\normal1" (glob) (windows !)
+  */no-largefiles/normal1 */no-largefiles/normal1 (glob) (no-windows !)
+  [1]
   $ hg -R subrepo-root revert --all
   reverting subrepo-root/.hglf/large (glob)
   reverting subrepo no-largefiles