diff --git a/plugins/OptionalManager/ContentDbPlugin.py b/plugins/OptionalManager/ContentDbPlugin.py
index a083f621..8de3749d 100644
--- a/plugins/OptionalManager/ContentDbPlugin.py
+++ b/plugins/OptionalManager/ContentDbPlugin.py
@@ -346,6 +346,10 @@ class ContentDbPlugin(object):
         if not limit:
             limit = self.getOptionalLimitBytes()
 
+        if limit < 0:
+            self.log.debug("Invalid limit for optional files: %s" % limit)
+            return False
+
         size = self.execute("SELECT SUM(size) FROM file_optional WHERE is_downloaded = 1 AND is_pinned = 0").fetchone()[0]
         if not size:
             size = 0
diff --git a/src/Config.py b/src/Config.py
index 5ac0c536..fa41ba4c 100644
--- a/src/Config.py
+++ b/src/Config.py
@@ -10,7 +10,7 @@ class Config(object):
 
     def __init__(self, argv):
         self.version = "0.5.1"
-        self.rev = 1861
+        self.rev = 1862
         self.argv = argv
         self.action = None
         self.config_file = "zeronet.conf"