diff --git a/src/mio/yum.py b/src/mio/yum.py
index c74a5a30267bae4cf0421ca549c67c2914255ab5..bb368c4c540c38132d697565da144bd45e713d6a 100755
--- a/src/mio/yum.py
+++ b/src/mio/yum.py
@@ -99,7 +99,7 @@ def run(path, rpm, exclude):
     # a conflict.
     exclude_arg = map(lambda s: "-x %s" % s, exclude)
     update = "%s -c %s -e %s -d %s -y update %s" % (
-        CMD, f.name, verb, verb, "".join(exclude_arg))
+        CMD, f.name, verb, verb, " ".join(exclude_arg))
     mio.log.log(NORMAL, update)
     result = mio.daemon_cage.system(update)