diff --git a/steps/interpolate_visibilities.cwl b/steps/interpolate_visibilities.cwl
index e4dc74d9ce4d550912d61e62c7b4af6f66e98ced..086cbaf9c4ef74f59fb77e2cd188596a70acb038 100644
--- a/steps/interpolate_visibilities.cwl
+++ b/steps/interpolate_visibilities.cwl
@@ -3,24 +3,19 @@ cwlVersion: v1.0
 $namespaces:
   sbg: 'https://www.sevenbridges.com/'
 id: interpolate_visibilities
+
 baseCommand:
   - DPPP
-arguments: 
+arguments:
   - msout.datacolumn=INTERP_DATA
   - msin.datacolumn=DATA
-  - steps=[interpolate] 
+  - steps=[interpolate]
 inputs:
   - id: msin
     type: Directory
     inputBinding:
       prefix: 'msin='
       separate: false
-  - id: msout_name
-    default: out.MS
-    type: string
-    inputBinding:
-      prefix: 'msout='
-      separate: false
   - id: storage_manager
     type: string
     default: Dysco
@@ -39,12 +34,18 @@ inputs:
       prefix: 'interpolate.windowsize='
       separate: false
 
-outputs: 
+outputs:
   - id: msout
     type: Directory
     outputBinding:
-      glob: $(inputs.msout_name)
+      glob: $(inputs.msin)
 label: interpolate_visibilities
 hints:
   - class: DockerRequirement
     dockerPull: lofar/lofar-pipeline
+
+requirements:
+  - class: InitialWorkDirRequirement
+    listing:
+      - entry: $(inputs.msin)
+        writable: true