diff --git a/fsl_course/feat3/feedsRun5.py b/fsl_course/feat3/feedsRun5.py
index fb40cd197af87d69d8f7a11260ecdbc1ab4b1b34..b73cb9211c248b734ea1a560e9882a91d515a493 100755
--- a/fsl_course/feat3/feedsRun5.py
+++ b/fsl_course/feat3/feedsRun5.py
@@ -26,9 +26,10 @@ utils.run(cmd)
 
 # For conda version, default_flobs.flobs is in new location
 
-cmd = f'''sed -i 's,etc,data/feat5,g' {newFSF}'''
-utils.run(cmd) 
-
+with open(newFSF, 'rt') as f:
+    contents = f.read()
+with open(newFSF, 'wt') as f:
+    f.write(contents.replace('/etc/', '/data/feat5/'))
 
 # run FEAT
 utils.run("unset SGE_ROOT; feat {0}".format(op.join(outDir, "design.fsf")))