diff --git a/jeepyb/cmd/run_mirror.py b/jeepyb/cmd/run_mirror.py
index 6062497..7e49b92 100644
--- a/jeepyb/cmd/run_mirror.py
+++ b/jeepyb/cmd/run_mirror.py
@@ -76,7 +76,7 @@
     PIP_DOWNLOAD_CACHE = os.environ.get('PIP_DOWNLOAD_CACHE',
                                         '/var/cache/pip')
     GIT_SOURCE = os.environ.get('GIT_SOURCE', 'https://github.com')
-    pip_format = "%s install -M -U %s --exists-action=w -b %s -r %s"
+    pip_format = "%s install -U %s --exists-action=w -b %s -r %s"
     venv_format = ("/usr/local/bin/virtualenv --clear --distribute "
                    "--extra-search-dir=%s %s")