diff --git a/tests/run-tests.py b/tests/run-tests.py
index 3eb99f8e9a6203d8a50008e5f68aa3235a7dae66_dGVzdHMvcnVuLXRlc3RzLnB5..42ed0780ec4bbc02d515156b9ff05bae3f9a171e_dGVzdHMvcnVuLXRlc3RzLnB5 100755
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -689,6 +689,10 @@
         hgrc.write('commit = -d "0 0"\n')
         hgrc.write('shelve = --date "0 0"\n')
         hgrc.write('tag = -d "0 0"\n')
+        hgrc.write('[largefiles]\n')
+        hgrc.write('usercache = %s\n' %
+                   (os.path.join(self._testtmp, '.cache/largefiles')))
+
         for opt in self._extraconfigopts:
             section, key = opt.split('.', 1)
             assert '=' in key, ('extra config opt %s must '
diff --git a/tests/test-basic.t b/tests/test-basic.t
index 3eb99f8e9a6203d8a50008e5f68aa3235a7dae66_dGVzdHMvdGVzdC1iYXNpYy50..42ed0780ec4bbc02d515156b9ff05bae3f9a171e_dGVzdHMvdGVzdC1iYXNpYy50 100644
--- a/tests/test-basic.t
+++ b/tests/test-basic.t
@@ -5,6 +5,7 @@
   defaults.commit=-d "0 0"
   defaults.shelve=--date "0 0"
   defaults.tag=-d "0 0"
+  largefiles.usercache=$TESTTMP/.cache/largefiles (glob)
   ui.slash=True
   ui.interactive=False
   ui.mergemarkers=detailed
diff --git a/tests/test-commandserver.t b/tests/test-commandserver.t
index 3eb99f8e9a6203d8a50008e5f68aa3235a7dae66_dGVzdHMvdGVzdC1jb21tYW5kc2VydmVyLnQ=..42ed0780ec4bbc02d515156b9ff05bae3f9a171e_dGVzdHMvdGVzdC1jb21tYW5kc2VydmVyLnQ= 100644
--- a/tests/test-commandserver.t
+++ b/tests/test-commandserver.t
@@ -178,6 +178,7 @@
   defaults.commit=-d "0 0"
   defaults.shelve=--date "0 0"
   defaults.tag=-d "0 0"
+  largefiles.usercache=$TESTTMP/.cache/largefiles
   ui.slash=True
   ui.interactive=False
   ui.mergemarkers=detailed