diff --git a/scripts/update/update.py b/scripts/update/update.py
index 7fa4344d5b..bf4655d35e 100644
--- a/scripts/update/update.py
+++ b/scripts/update/update.py
@@ -14,18 +14,18 @@ _src_dir = lambda *p: os.path.join(settings.SRC_DIR, *p)
 @task
 def create_virtualenv(ctx):
     venv = settings.VIRTUAL_ENV
-    try:
-        try:
-            ctx.local("virtualenv --distribute --never-download %s" % venv)
-        except BadReturnCode:
-            pass # if this is really broken, then the pip install should fail
+    if not venv.startswith('/data'):
+        raise Exception('venv must start with /data')
 
-        ctx.local("%s/bin/pip install --exists-action=w --no-deps --no-index --download-cache=/tmp/pip-cache -f %s -r %s/requirements/prod.txt" %
-                    (venv, settings.PYREPO, settings.SRC_DIR))
-    finally:
-        # make sure this always runs
-        ctx.local("rm -f %s/lib/python2.6/no-global-site-packages.txt" % venv)
-        ctx.local("%s/bin/python /usr/bin/virtualenv --relocatable %s" % (venv, venv))
+    ctx.local('rm -rf %s' % venv)
+    ctx.local('virtualenv --distribute --never-download %s' % venv)
+
+    ctx.local("%s/bin/pip install --exists-action=w --no-deps --no-index --download-cache=/tmp/pip-cache -f %s -r %s/requirements/prod.txt" %
+                (venv, settings.PYREPO, settings.SRC_DIR))
+
+    # make sure this always runs
+    ctx.local("rm -f %s/lib/python2.6/no-global-site-packages.txt" % venv)
+    ctx.local("%s/bin/python /usr/bin/virtualenv --relocatable %s" % (venv, venv))
 
 
 @task