1 files changed, 7 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
index 157e75dbf7..0cf40de70f 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_definitions.rb
@@ -3,7 +3,10 @@ module ActiveRecord
     module MySQL
       module ColumnMethods
         def primary_key(name, type = :primary_key, **options)
-          options[:auto_increment] = true if type == :bigint && !options.key?(:default)
+          if type == :primary_key && !options.key?(:default)
+            options[:auto_increment] = true
+            options[:limit] = 8
+          end
           super
         end
 
@@ -80,9 +83,9 @@ module ActiveRecord
 
         private
 
-        def create_column_definition(name, type)
-          MySQL::ColumnDefinition.new(name, type)
-        end
+          def create_column_definition(name, type)
+            MySQL::ColumnDefinition.new(name, type)
+          end
       end
 
       class Table < ActiveRecord::ConnectionAdapters::Table