diff --git a/biblio-tools/v1/openalex/works/expand.ini b/biblio-tools/v1/openalex/works/expand.ini
index 7f8eb8b..f776d07 100644
--- a/biblio-tools/v1/openalex/works/expand.ini
+++ b/biblio-tools/v1/openalex/works/expand.ini
@@ -33,7 +33,7 @@
 cacheName = post-v1-openalex-works-expand
 
 [expand/URLFetch]
-url = get('value').prepend('https://api.openalex.org/works/doi:')
+url = get('value').prepend('https://api.openalex.org/works/doi:').append(`?api_key=${env('OPENALEX_API_KEY')}`)
 json = true
 target = fix('value')
 timeout = 30000
diff --git a/biblio-tools/v2/openalex/works/expand.ini b/biblio-tools/v2/openalex/works/expand.ini
index c855d9b..10b6b91 100644
--- a/biblio-tools/v2/openalex/works/expand.ini
+++ b/biblio-tools/v2/openalex/works/expand.ini
@@ -33,7 +33,7 @@
 cacheName = post-v2-openalex-works-expand
 
 [expand/URLFetch]
-url = get('value').prepend('https://api.openalex.org/works/doi:')
+url = get('value').prepend('https://api.openalex.org/works/doi:').append(`?api_key=${env('OPENALEX_API_KEY')}`)
 json = true
 target = fix('value')
 timeout = 30000