diff --git a/steps/DP3.ParsetGenerator.cwl b/steps/DP3.ParsetGenerator.cwl
index fdb5d66d470ff3257c9c770ded3d14531b3b16a7..c810ac8a343b59bd8b45f285b14051c7acb0e3c3 100644
--- a/steps/DP3.ParsetGenerator.cwl
+++ b/steps/DP3.ParsetGenerator.cwl
@@ -66,9 +66,9 @@ outputs:
       outputEval: |-
         ${
         var outfiles = []
-        for(let step in inputs.parameters_input){
+        for(var step in inputs.parameters_input){
           step = inputs.parameters_input[step]
-          for(let parameter in step['parameters']){
+          for(var parameter in step['parameters']){
             parameter = step['parameters'][parameter]
 
             if (parameter != null && parameter.class =='File'){
@@ -85,9 +85,9 @@ outputs:
       outputEval: |
         ${
         var outdirs = []
-        for(let step in inputs.parameters_input){
+        for(var step in inputs.parameters_input){
           step = inputs.parameters_input[step]
-          for(let parameter in step['parameters']){
+          for(var parameter in step['parameters']){
             parameter = step['parameters'][parameter]
             if (parameter != null && parameter.class=='Directory'){
               outdirs.push(parameter)