1 files changed, 5 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index ec25bbf18e..e12924e63f 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -513,7 +513,7 @@ module ActiveRecord
       def change_column(table_name, column_name, type, options = {}) #:nodoc:
         column = column_for(table_name, column_name)
 
-        unless options_include_default?(options)
+        if has_default?(type) && !options_include_default?(options)
           options[:default] = column.default
         end
 
@@ -675,6 +675,10 @@ module ActiveRecord
           end
           column
         end
+
+        def has_default?(sql_type)
+          sql_type =~ :binary || sql_type == :text #mysql forbids defaults on blob and text columns
+        end
     end
   end
 end