diff --git a/subworkflow/pol_align.cwl b/subworkflow/pol_align.cwl
index 33743b6623326dc1f3231395429d9eb44ba43a82..ee2d7dbd423bec7b6b0e1d97b3412f01c38ee105 100644
--- a/subworkflow/pol_align.cwl
+++ b/subworkflow/pol_align.cwl
@@ -90,4 +90,5 @@ steps:
     run: ../lofar-cwl/steps/LoSoTo.Residual.cwl
     'sbg:x': -0.012040258385241032
     'sbg:y': -287.7294006347656
-requirements: []
+requirements:
+  MultipleInputFeatureRequirement: {}