diff --git a/docker-compose.yml b/docker-compose.yml
index 215762e..e39a255 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -64,7 +64,17 @@ services:
     image: ${GITEA_REGISTRY_IMAGE}
     container_name: claude-agent
     restart: unless-stopped
-    env_file: .env
+    # Explicit vars, not env_file: .env — Portainer's git-based stack deploy clones the
+    # repo fresh (no .env present, it's gitignored) and only performs ${VAR} substitution
+    # from the stack's own Env list, so env_file here would silently fail to load anything.
+    environment:
+      GITEA_URL: ${GITEA_URL}
+      GITEA_TOKEN: ${GITEA_TOKEN}
+      GITEA_WEBHOOK_SECRET: ${GITEA_WEBHOOK_SECRET}
+      ANTHROPIC_API_KEY: ${ANTHROPIC_API_KEY}
+      MATRIX_HOMESERVER_URL: ${MATRIX_HOMESERVER_URL}
+      MATRIX_BOT_TOKEN: ${MATRIX_BOT_TOKEN}
+      MATRIX_CONTROL_ROOM_ID: ${MATRIX_CONTROL_ROOM_ID}
     volumes:
       - agent_workspace:/workspace
     networks: