diff --git a/CHANGELOG b/CHANGELOG
index 25067d3abe259b955bd8dab420b465358d1e27ca..7c177b3139a9540183c81aca7caeadcb2f878a3c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -18,6 +18,7 @@ v 6.8.0
   - Expose event and mergerequest timestamps in API
   - Fix emails on push service when only one commit is pushed
   - Store Rails cache data in the Redis `cache:gitlab` namespace
+  - Adjust MySQL limits for existing installations
 
 v 6.7.3
   - Fix the merge notification email not being sent (Pierre de La Morinerie)
diff --git a/db/migrate/20140415124820_limits_to_mysql.rb b/db/migrate/20140415124820_limits_to_mysql.rb
new file mode 100644
index 0000000000000000000000000000000000000000..3f6e62617c57ab82367fafd407c89815c504c34d
--- /dev/null
+++ b/db/migrate/20140415124820_limits_to_mysql.rb
@@ -0,0 +1 @@
+require_relative 'limits_to_mysql'
diff --git a/db/migrate/limits_to_mysql.rb b/db/migrate/limits_to_mysql.rb
new file mode 100644
index 0000000000000000000000000000000000000000..4dc3b830bc6c87bc49f2d154c63609a7a49a83e4
--- /dev/null
+++ b/db/migrate/limits_to_mysql.rb
@@ -0,0 +1,10 @@
+class LimitsToMysql < ActiveRecord::Migration
+  def up
+    return unless ActiveRecord::Base.configurations[Rails.env]['adapter'] == 'mysql2'
+
+    change_column :merge_request_diffs, :st_commits, :text, limit: 2147483647
+    change_column :merge_request_diffs, :st_diffs, :text, limit: 2147483647
+    change_column :snippets, :content, :text, limit: 2147483647
+    change_column :notes, :st_diff, :text, limit: 2147483647
+  end
+end
diff --git a/lib/tasks/migrate/add_limits_mysql.rake b/lib/tasks/migrate/add_limits_mysql.rake
index 46b6451752b5bca5de8a756094e05d796434cf23..a1972a682d8512766e8dd6b6c6d24ab44c812461 100644
--- a/lib/tasks/migrate/add_limits_mysql.rake
+++ b/lib/tasks/migrate/add_limits_mysql.rake
@@ -1,14 +1,7 @@
+require Rails.root.join('db/migrate/limits_to_mysql')
+
 desc "GITLAB | Add limits to strings in mysql database"
 task add_limits_mysql: :environment do
   puts "Adding limits to schema.rb for mysql"
   LimitsToMysql.new.up
 end
-
-class LimitsToMysql < ActiveRecord::Migration
-  def up
-    change_column :merge_request_diffs, :st_commits, :text, limit: 2147483647
-    change_column :merge_request_diffs, :st_diffs, :text, limit: 2147483647
-    change_column :snippets, :content, :text, limit: 2147483647
-    change_column :notes, :st_diff, :text, limit: 2147483647
-  end
-end