diff --git a/compose.yaml b/compose.yaml
index ad095d8..1c21eba 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -15,6 +15,7 @@ services:
       - flaskpaste-data:/app/data
     environment:
       - FLASK_ENV=production
+      - FLASKPASTE_URL_PREFIX=/paste    # HAProxy strips this before forwarding
       - FLASKPASTE_EXPIRY=432000        # 5 days
       - FLASKPASTE_MAX_ANON=3145728     # 3 MiB
       - FLASKPASTE_MAX_AUTH=52428800    # 50 MiB