diff --git a/client/nginx.conf b/client/nginx.conf
index e194e50b..0210b1d6 100644
--- a/client/nginx.conf
+++ b/client/nginx.conf
@@ -8,7 +8,7 @@ server {
   location /api {
     set $api_key $API_KEY;
     proxy_pass https://cluster-production.elasticsearch.dataesr.ovh;
-    proxy_set_header Authorization Basic $api_key;
+    proxy_set_header Authorization 'Basic $api_key';
     proxy_set_header Accept application/json;
     proxy_set_header Content-Type application/json;
     client_max_body_size 10M;