2 files changed, 4 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
index 24dcf852e1..9ad6a6c0d0 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
@@ -2,6 +2,8 @@ module ActiveRecord
   module ConnectionAdapters
     module MySQL
       class TypeMetadata < DelegateClass(SqlTypeMetadata) # :nodoc:
+        undef to_yaml if method_defined?(:to_yaml)
+
         attr_reader :extra
 
         def initialize(type_metadata, extra: "")
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
index 311988625f..f57179ae59 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
@@ -1,6 +1,8 @@
 module ActiveRecord
   module ConnectionAdapters
     class PostgreSQLTypeMetadata < DelegateClass(SqlTypeMetadata)
+      undef to_yaml if method_defined?(:to_yaml)
+
       attr_reader :oid, :fmod, :array
 
       def initialize(type_metadata, oid: nil, fmod: nil)