diff --git a/fdroidserver/update.py b/fdroidserver/update.py
index fff53419..1a5cd3d4 100644
--- a/fdroidserver/update.py
+++ b/fdroidserver/update.py
@@ -232,7 +232,7 @@ def scan_apks(apps, apkcache, repodir, knownapks):
     apks = []
     for apkfile in glob.glob(os.path.join(repodir, '*.apk')):
 
-        apkfilename = apkfile[len(repodir):]
+        apkfilename = apkfile[len(repodir) + 1:]
         if apkfilename.find(' ') != -1:
             print "No spaces in APK filenames!"
             sys.exit(1)