diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 4edb64c2c05e2..1bb1c0bc1538e 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -8,7 +8,8 @@ def self.define_all_hashes_method!
     raise 'Mysql not loaded' unless defined?(::Mysql)
 
     target = defined?(Mysql::Result) ? Mysql::Result : MysqlRes
-    return if target.instance_methods.include?('all_hashes')
+    return if target.instance_methods.include?('all_hashes') ||
+              target.instance_methods.include?(:all_hashes)
 
     # Ruby driver has a version string and returns null values in each_hash
     # C driver >= 2.7 returns null values in each_hash