diff --git a/src/middleware/route-ratelimit.js b/src/middleware/route-ratelimit.js
index 2f6dfad..4ca8510 100644
--- a/src/middleware/route-ratelimit.js
+++ b/src/middleware/route-ratelimit.js
@@ -138,7 +138,7 @@ class RateLimits {
         // Apply paid-access rate limits based on key/IP
         if (
           key.toString().indexOf('172.17.') > -1 ||
-          key.toString.indexOf('::ffff:127.0.0.1') > -1
+          key.toString().indexOf('::ffff:127.0.0.1') > -1
         ) {
           pointsToConsume = 1
           res.locals.pointsToConsume = pointsToConsume // Feedback for tests.