diff --git a/tests/test_raid.py b/tests/test_raid.py
index e68e4958132007d6e5c0e9c4f2f180d033e837b8..ffce264853fe539904b92dd57660e61a1759e58b 100755
--- a/tests/test_raid.py
+++ b/tests/test_raid.py
@@ -21,7 +21,7 @@ def print_green(string):
     print(GREEN + string + DEF)
 
 def check_raid(dev):
-    cmd = 'mdadm -D /dev/%s' % dev
+    cmd = 'mdadm -D %s' % dev
     status, output = subprocess.getstatusoutput(cmd)
     print(output)
     return status != 0