diff --git a/src/danog/MadelineProto/Db/MysqlArray.php b/src/danog/MadelineProto/Db/MysqlArray.php
index ed72dc0d..614e99e0 100644
--- a/src/danog/MadelineProto/Db/MysqlArray.php
+++ b/src/danog/MadelineProto/Db/MysqlArray.php
@@ -353,6 +353,13 @@ class MysqlArray implements DbArray
                 return [];
             }
 
+            if (
+                !empty($params['index'])
+                && !mb_check_encoding($params['index'], 'UTF-8')
+            ) {
+                $params['index'] = mb_convert_encoding($params['index'], 'UTF-8');
+            }
+
             try {
                 $request = yield $this->db->execute($query, $params);
             } catch (\Throwable $e) {
diff --git a/src/danog/MadelineProto/Db/PostgresArray.php b/src/danog/MadelineProto/Db/PostgresArray.php
index 213c26ba..995affe4 100644
--- a/src/danog/MadelineProto/Db/PostgresArray.php
+++ b/src/danog/MadelineProto/Db/PostgresArray.php
@@ -365,6 +365,13 @@ class PostgresArray implements DbArray
                 return [];
             }
 
+            if (
+                !empty($params['index'])
+                && !mb_check_encoding($params['index'], 'UTF-8')
+            ) {
+                $params['index'] = mb_convert_encoding($params['index'], 'UTF-8');
+            }
+
             try {
                 $request = yield $this->db->execute($query, $params);
             } catch (\Throwable $e) {