diff --git a/src/Activation/ActivationModule.php b/src/Activation/ActivationModule.php
index 427d97681..eedeb7cec 100644
--- a/src/Activation/ActivationModule.php
+++ b/src/Activation/ActivationModule.php
@@ -68,6 +68,7 @@ public function initDb()
                     post_id bigint NOT NULL,
                     expired_time int NOT NULL,
                     PRIMARY KEY id (id)
+                    COLLATE=utf8mb4_unicode_ci
                 );";
                 dbDelta($sql);