diff --git a/bin/build b/bin/build
index 59f6f011..8e2a6518 100755
--- a/bin/build
+++ b/bin/build
@@ -50,5 +50,5 @@ echo "Finished."
 # build API documentation
 echo 'building api documentation...'
 cd ./src/api-docs
-bundle install --path=../../build/vendor
-bundle exec middleman build --clean --build-dir=../../build/api-docs
+BUNDLE_PATH="../../build/vendor" bundle install --jobs 4
+BUNDLE_PATH="../../build/vendor" bundle exec middleman build --clean --build-dir=../../build/api-docs
diff --git a/src/api-docs/Gemfile b/src/api-docs/Gemfile
index 1c28e61d..62191d06 100644
--- a/src/api-docs/Gemfile
+++ b/src/api-docs/Gemfile
@@ -8,7 +8,7 @@ gem 'middleman-autoprefixer', '~> 2.7.0'
 gem 'middleman-livereload', '~> 3.4.7'
 gem 'middleman-sprockets', '~> 4.1.1'
 gem 'rouge', '~> 3.28.0'
-gem 'redcarpet', '~> 3.5.1'
+gem 'redcarpet'
 gem 'nokogiri', '~> 1.13.4'
 gem 'rack', '~> 2.2.3'
 gem 'webrick', '~> 1.7.0'
diff --git a/src/api-docs/Gemfile.lock b/src/api-docs/Gemfile.lock
index 5f28e167..6955a9c0 100644
--- a/src/api-docs/Gemfile.lock
+++ b/src/api-docs/Gemfile.lock
@@ -108,7 +108,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    redcarpet (3.5.1)
+    redcarpet (3.6.0)
     rexml (3.2.5)
     rouge (3.28.0)
     sassc (2.4.0)
@@ -139,7 +139,7 @@ DEPENDENCIES
   middleman-syntax (~> 3.2.0)
   nokogiri (~> 1.13.4)
   rack (~> 2.2.3)
-  redcarpet (~> 3.5.1)
+  redcarpet
   rouge (~> 3.28.0)
   webrick (~> 1.7.0)