diff --git a/fsl_course/feat3/feedsRun3.py b/fsl_course/feat3/feedsRun3.py
index 019d6d9c9a6a538096ad6d0337a973fff50b947e..d27b71a33235018a1a18c19c0f162bd0f624dba9 100755
--- a/fsl_course/feat3/feedsRun3.py
+++ b/fsl_course/feat3/feedsRun3.py
@@ -10,6 +10,7 @@ import glob
 import nibabel as nb
 import numpy as np
 import hashlib
+import re
 import shutil
 
 def run(cmd):
@@ -34,12 +35,13 @@ newFeatDir = op.join(outDir, op.basename(origFeatDir))
 
 cmd = "./cleanFSF.py {0} {1} {2} {3} {4} {5}".format(
     origFSF, newFSF, origDataDir, dataDir, outDir, origFSLDir)
-
-run(cmd)
-cmd = """sed -ie 's|set feat_files(1).*|set feat_files(1) "{0}"|g' {1}""".format(newFeatDir,newFSF)
-print(cmd)
 run(cmd)
 
+#The output FEAT directory will be the copied input, so update fsf
+text = open(newFSF, 'rt').read()
+text = re.sub('set feat_files\(1\).*',  f'set feat_files(1) "{newFeatDir}"', text)
+open(newFSF, 'wt').write(text)
+
 # run FEAT
 shutil.copytree(origFeatDir,newFeatDir)
 run("chmod -R a+w {0}".format(newFeatDir))