diff --git a/scripts/upgrade.py b/scripts/upgrade.py
index 0593016..82cc1cc 100755
--- a/scripts/upgrade.py
+++ b/scripts/upgrade.py
@@ -75,9 +75,12 @@ def install_command(url):
    tmp = tempfile.mkdtemp()
    if call(["/bin/sh", "-c", 'cd %s; curl %s | tar xzv' % (tmp, url)]) == 0:
       for f in os.listdir(tmp):
+         dest = os.path.join(seaf_home, os.path.basename(f))
          if len(re.findall(version_re, f)) > 0:
-             dest = os.path.join(seaf_home, os.path.basename(f))
-             shutil.move(os.path.join(tmp,f), dest)
+             if not os.path.exists(dest):           
+                shutil.move(os.path.join(tmp,f), dest)
+             else:
+                print("Found previous installation, resuming setup")
              current = current_version()
              target_version = ''.join(re.findall(version_re,dest))
              if len(current) == 1: current = current[0]