diff --git a/src/lib/constants.js b/src/lib/constants.js
index 630e387..7bf446b 100644
--- a/src/lib/constants.js
+++ b/src/lib/constants.js
@@ -13,7 +13,8 @@ export const CREDIT_REGEN_RATE = 1; // credits per second
 export const MAX_CREDITS = 256;
 
 /** Redis keys */
-export const REDIS_CANVAS_KEY = 'canvas';
+export const REDIS_KEY_PREFIX = 'rplace:';
+export const REDIS_CANVAS_KEY = `${REDIS_KEY_PREFIX}canvas`;
 
 /** 32-color palette from rplace.live (hex values) */
 export const COLORS = [
diff --git a/src/lib/rate-limiter.js b/src/lib/rate-limiter.js
index 06ee265..7a65c47 100644
--- a/src/lib/rate-limiter.js
+++ b/src/lib/rate-limiter.js
@@ -1,5 +1,5 @@
 import { getRedis } from './redis-client.js';
-import { MAX_CREDITS, CREDIT_REGEN_RATE } from './constants.js';
+import { MAX_CREDITS, CREDIT_REGEN_RATE, REDIS_KEY_PREFIX } from './constants.js';
 
 /**
  * Lua script for atomic check-and-deduct of stackable credits.
@@ -41,7 +41,7 @@ return {1, remaining, 0}
 export async function checkAndDeductCredits(env, userId, count) {
   const redis = getRedis(env);
   const now = Math.floor(Date.now() / 1000);
-  const key = `credits:${userId}`;
+  const key = `${REDIS_KEY_PREFIX}credits:${userId}`;
 
   const result = await redis.eval(
     CREDIT_SCRIPT,