diff --git a/server/index.ts b/server/index.ts
index c0e4431..963a7ca 100644
--- a/server/index.ts
+++ b/server/index.ts
@@ -35,7 +35,7 @@ const levels = createLevelRepository(pool, editingEnabled, objectStorage, eviden
 const narrative = createNarrativeRepository(pool, objectStorage)
 const storyGraph = createStoryGraphRepository(pool)
 const users = createUserRepository(pool)
-const AUTH_COOKIE = { httpOnly: true, sameSite: 'lax' as const, path: '/', maxAge: 30 * 24 * 60 * 60 * 1000 }
+const AUTH_COOKIE = { httpOnly: true, secure: process.env.NODE_ENV === 'production', sameSite: 'lax' as const, path: '/', maxAge: 30 * 24 * 60 * 60 * 1000 }
 const STORY_NODE_TYPES: StoryNodeType[] = ['cutscene', 'dialogue', 'level', 'det_gate', 'llm_gate', 'merit', 'phone']
 
 function wantsEdit(req: express.Request) {