diff --git a/.github/actions/purge-m365-data/action.yml b/.github/actions/purge-m365-data/action.yml
index dd67f2326..cf013a054 100644
--- a/.github/actions/purge-m365-data/action.yml
+++ b/.github/actions/purge-m365-data/action.yml
@@ -89,4 +89,4 @@ runs:
       env:
         M365_TENANT_ADMIN_USER: ${{ inputs.m365-admin-user }}
         M365_TENANT_ADMIN_PASSWORD: ${{ inputs.m365-admin-password }}
-      run: ./onedrivePurge.ps1 -Site ${{ inputs.site }} -LibraryNameList "${{ inputs.libraries }}".split(",") -FolderPrefixPurgeList ${{ inputs.folder-prefix }} -LibraryPrefixDeleteList ${{ inputs.library-prefix }} -PurgeBeforeTimestamp ${{ inputs.older-than }}
+      run: ./onedrivePurge.ps1 -Site ${{ inputs.site }} -LibraryNameList "${{ inputs.libraries }}".split(",") -FolderPrefixPurgeList ${{ inputs.folder-prefix }} -LibraryPrefixDeleteList ${{ inputs.library-prefix && inputs.library-prefix || '[]' }} -PurgeBeforeTimestamp ${{ inputs.older-than }}