diff --git a/fsl/utils/callfsl.py b/fsl/utils/callfsl.py
index a77cbc40113c6ed080b64ff3213b707df13d8736..fa68a3f4d4fdb46324de5484563de8976114c7f5 100644
--- a/fsl/utils/callfsl.py
+++ b/fsl/utils/callfsl.py
@@ -35,7 +35,7 @@ def callFSL(*args):
     # assume it is a sequence containing
     # separate command and arguments.
     if len(args) == 1:
-        args = args.split()
+        args = args[0].split()
 
     args    = list(args)
     args[0] = op.join(fslplatform.fsldir, 'bin', args[0])