diff --git a/.github/workflows/call-universal_test_workflow.yaml b/.github/workflows/call-universal_test_workflow.yaml
index 1ec84bed..740c7893 100644
--- a/.github/workflows/call-universal_test_workflow.yaml
+++ b/.github/workflows/call-universal_test_workflow.yaml
@@ -103,6 +103,8 @@ jobs:
           # Generated from workflow input custom_testplan_yaml
           ${{ inputs.custom_testplan_yaml }}
           EOF
+          # The next line can be removed in v5 when the transition to yaml is finished
+          cp '${{ inputs.plan_folder }}/_custom.yaml' '${{ inputs.plan_folder }}/_custom.yml'
           TESTPLAN=$(echo "${{ inputs.testplan }}"|sed -e 's|~|${{ inputs.plan_folder }}|g')
           echo "testplan=${{ inputs.plan_folder }}/defaults/defaults.yaml,${TESTPLAN}" >>"${GITHUB_OUTPUT}"
 
diff --git a/.github/workflows/call-universal_test_workflow.yml b/.github/workflows/call-universal_test_workflow.yml
index 1ec84bed..740c7893 100644
--- a/.github/workflows/call-universal_test_workflow.yml
+++ b/.github/workflows/call-universal_test_workflow.yml
@@ -103,6 +103,8 @@ jobs:
           # Generated from workflow input custom_testplan_yaml
           ${{ inputs.custom_testplan_yaml }}
           EOF
+          # The next line can be removed in v5 when the transition to yaml is finished
+          cp '${{ inputs.plan_folder }}/_custom.yaml' '${{ inputs.plan_folder }}/_custom.yml'
           TESTPLAN=$(echo "${{ inputs.testplan }}"|sed -e 's|~|${{ inputs.plan_folder }}|g')
           echo "testplan=${{ inputs.plan_folder }}/defaults/defaults.yaml,${TESTPLAN}" >>"${GITHUB_OUTPUT}"
 
diff --git a/.github/workflows/universal_workflow_light.yaml b/.github/workflows/universal_workflow_light.yaml
index 91eea08a..9450cc65 100644
--- a/.github/workflows/universal_workflow_light.yaml
+++ b/.github/workflows/universal_workflow_light.yaml
@@ -103,6 +103,8 @@ jobs:
           # Generated from workflow input custom_testplan_yaml
           ${{ inputs.custom_testplan_yaml }}
           EOF
+          # The next line can be removed in v5 when the transition to yaml is finished
+          cp '${{ inputs.plan_folder }}/_custom.yaml' '${{ inputs.plan_folder }}/_custom.yml'
           if [ '${{ github.event_name }}' == 'pull_request' ]; then
             REF=$(echo '{{ .Github.HeadRef }}'|sed -e 's|/refs/heads/||')
             # This is the git ref name
diff --git a/.github/workflows/universal_workflow_light.yml b/.github/workflows/universal_workflow_light.yml
index 91eea08a..9450cc65 100644
--- a/.github/workflows/universal_workflow_light.yml
+++ b/.github/workflows/universal_workflow_light.yml
@@ -103,6 +103,8 @@ jobs:
           # Generated from workflow input custom_testplan_yaml
           ${{ inputs.custom_testplan_yaml }}
           EOF
+          # The next line can be removed in v5 when the transition to yaml is finished
+          cp '${{ inputs.plan_folder }}/_custom.yaml' '${{ inputs.plan_folder }}/_custom.yml'
           if [ '${{ github.event_name }}' == 'pull_request' ]; then
             REF=$(echo '{{ .Github.HeadRef }}'|sed -e 's|/refs/heads/||')
             # This is the git ref name