diff --git a/CHANGELOG b/CHANGELOG
index e13e0eef87a0e1e57fd504ecf2a97cc00818757f..b2a406b0def32dfa10c1cec89904c6117b061fc3 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -109,6 +109,9 @@ v 8.13.0 (unreleased)
   - API: all unknown routing will be handled with 404 Not Found
   - Make guests unable to view MRs on private projects
 
+v 8.12.7
+  - Use gitlab-markup gem instead of github-markup to fix `.rst` file rendering. !6659
+
 v 8.12.6
   - Update mailroom to 0.8.1 in Gemfile.lock  !6814
 
diff --git a/Gemfile b/Gemfile
index 7323776d24c3c53843093c0448a3d462cace187f..1204a546983b427287bc574922640dc5b278fac9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -101,7 +101,7 @@ gem 'seed-fu', '~> 2.3.5'
 # Markdown and HTML processing
 gem 'html-pipeline',      '~> 1.11.0'
 gem 'deckar01-task_list', '1.0.5', require: 'task_list/railtie'
-gem 'github-markup',      '~> 1.4', git: 'https://github.com/brodock/github-markup.git', branch: 'python3-fix'
+gem 'gitlab-markup',      '~> 1.5.0'
 gem 'redcarpet',          '~> 3.3.3'
 gem 'RedCloth',           '~> 4.3.2'
 gem 'rdoc',               '~>3.6'
diff --git a/Gemfile.lock b/Gemfile.lock
index dde92fff044daf1ba56e040944b015ceb8877434..25a176da8fd4e6f112702c544fdb9af2121b10b0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,10 +1,3 @@
-GIT
-  remote: https://github.com/brodock/github-markup.git
-  revision: 62ff5993081920ad75016f2b87019dd14e3af137
-  branch: python3-fix
-  specs:
-    github-markup (1.4.0)
-
 GEM
   remote: https://rubygems.org/
   specs:
@@ -279,6 +272,7 @@ GEM
       escape_utils (~> 1.1.0)
       mime-types (>= 1.19)
       rugged (>= 0.23.0b)
+    github-markup (1.4.0)
     gitlab-flowdock-git-hook (1.0.1)
       flowdock (~> 0.7)
       gitlab-grit (>= 2.4.1)
@@ -288,6 +282,7 @@ GEM
       diff-lcs (~> 1.1)
       mime-types (>= 1.16, < 3)
       posix-spawn (~> 0.3)
+    gitlab-markup (1.5.0)
     gitlab_git (10.6.8)
       activesupport (~> 4.0)
       charlock_holmes (~> 0.7.3)
@@ -870,8 +865,8 @@ DEPENDENCIES
   gemnasium-gitlab-service (~> 0.2)
   gemojione (~> 3.0)
   github-linguist (~> 4.7.0)
-  github-markup (~> 1.4)!
   gitlab-flowdock-git-hook (~> 1.0.1)
+  gitlab-markup (~> 1.5.0)
   gitlab_git (~> 10.6.8)
   gitlab_omniauth-ldap (~> 1.2.1)
   gollum-lib (~> 4.2)