diff --git a/lofar-cwl/steps/DPPP.cwl b/lofar-cwl/steps/DPPP.cwl
index b15ffd78908c17baa23ce66380b2414fa8f6ef5a..8cd5a42291642598cd7fc2884a491b254246c476 100755
--- a/lofar-cwl/steps/DPPP.cwl
+++ b/lofar-cwl/steps/DPPP.cwl
@@ -141,3 +141,6 @@ requirements:
     listing:
       - entry: $(inputs.msin)
         writable: true
+      - entry: $(inputs.secondary_files)
+      - entry: $(inputs.secondary_directories)
+