diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 5f512758e92e0982f2abe721632094079f7ce957..26015528e5cc9cc29d3abb98603d88d28c03f719 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -648,6 +648,8 @@ def valid_type?(type)
       def initialize_type_map(m) # :nodoc:
         super
 
+        register_class_with_limit m, %r(char)i, MysqlString
+
         m.register_type %r(tinytext)i,   Type::Text.new(limit: 2**8 - 1)
         m.register_type %r(tinyblob)i,   Type::Binary.new(limit: 2**8 - 1)
         m.register_type %r(text)i,       Type::Text.new(limit: 2**16 - 1)
@@ -672,7 +674,7 @@ def initialize_type_map(m) # :nodoc:
         m.register_type(%r(enum)i) do |sql_type|
           limit = sql_type[/^enum\((.+)\)/i, 1]
             .split(',').map{|enum| enum.strip.length - 2}.max
-          Type::String.new(limit: limit)
+          MysqlString.new(limit: limit)
         end
       end
 
@@ -847,6 +849,26 @@ def extract_foreign_key_action(structure, name, action) # :nodoc:
           end
         end
       end
+
+      class MysqlString < Type::String # :nodoc:
+        def type_cast_for_database(value)
+          case value
+          when true then "1"
+          when false then "0"
+          else super
+          end
+        end
+
+        private
+
+        def cast_value(value)
+          case value
+          when true then "1"
+          when false then "0"
+          else super
+          end
+        end
+      end
     end
   end
 end
diff --git a/activerecord/lib/active_record/type/string.rb b/activerecord/lib/active_record/type/string.rb
index 150defb106584feb8152bb212fc97a4357e264c2..fbc0af2c5a653a3808b6f859928a6b39a5b6b09b 100644
--- a/activerecord/lib/active_record/type/string.rb
+++ b/activerecord/lib/active_record/type/string.rb
@@ -15,8 +15,8 @@ def type_cast_for_database(value)
         case value
         when ::Numeric, ActiveSupport::Duration then value.to_s
         when ::String then ::String.new(value)
-        when true then "1"
-        when false then "0"
+        when true then "t"
+        when false then "f"
         else super
         end
       end
@@ -25,8 +25,8 @@ def type_cast_for_database(value)
 
       def cast_value(value)
         case value
-        when true then "1"
-        when false then "0"
+        when true then "t"
+        when false then "f"
         # String.new is slightly faster than dup
         else ::String.new(value.to_s)
         end
diff --git a/activerecord/test/cases/type/string_test.rb b/activerecord/test/cases/type/string_test.rb
index 420177ed4944d69c9fd20e7c65a28e3a6c8ed534..4d78f287f156a0a524b78a2713783d8eb88cfb49 100644
--- a/activerecord/test/cases/type/string_test.rb
+++ b/activerecord/test/cases/type/string_test.rb
@@ -4,8 +4,8 @@ module ActiveRecord
   class StringTypeTest < ActiveRecord::TestCase
     test "type casting" do
       type = Type::String.new
-      assert_equal "1", type.type_cast_from_user(true)
-      assert_equal "0", type.type_cast_from_user(false)
+      assert_equal "t", type.type_cast_from_user(true)
+      assert_equal "f", type.type_cast_from_user(false)
       assert_equal "123", type.type_cast_from_user(123)
     end