diff --git a/.github/workflows/ci_steps.yml b/.github/workflows/ci_steps.yml
index 853d8e103..522583ac9 100644
--- a/.github/workflows/ci_steps.yml
+++ b/.github/workflows/ci_steps.yml
@@ -50,7 +50,6 @@ jobs:
     env:
       ACTIONS_RUNNER_FORCE_ACTIONS_NODE_VERSION: node16
       ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
-      INSTALL_MANIFEST: _build/install_manifest.${{ inputs.os.split('-')[0] }}.${{ inputs.build }}.txt
 
     steps:
 
@@ -91,6 +90,8 @@ jobs:
                 -DOPENEXR_RUN_FUZZ_TESTS='OFF' \
                 -DCMAKE_VERBOSE_MAKEFILE='ON'"
           echo "CMAKE_COMMAND=$CMAKE_COMMAND" >> $GITHUB_ENV
+          echo "INSTALL_MANIFEST=$(echo '_build/install_manifest.${{ inputs.os }}' | cut -d'-').${{ inputs.build }}.txt" >> $GITHUB_ENV
+          echo 
         working-directory: _build
         shell: bash