diff --git a/ghost/core/core/server/services/members/content-gating.js b/ghost/core/core/server/services/members/content-gating.js
index 6a63a455211f..69e153475eeb 100644
--- a/ghost/core/core/server/services/members/content-gating.js
+++ b/ghost/core/core/server/services/members/content-gating.js
@@ -46,7 +46,7 @@ function checkPostAccess(post, member) {
             return BLOCK_ACCESS;
         }
         visibility = post.tiers.map((product) => {
-            return `product:${product.slug}`;
+            return `product:'${product.slug}'`;
         }).join(',');
     }