diff --git a/ci/travis.rb b/ci/travis.rb
index 3ccbd1dad4..a1920a7a1f 100755
--- a/ci/travis.rb
+++ b/ci/travis.rb
@@ -107,6 +107,7 @@ results = {}
 
 ENV['GEM'].split(',').each do |gem|
   [false, true].each do |isolated|
+    next if ENV['TRAVIS_PULL_REQUEST'] && ENV['TRAVIS_PULL_REQUEST'] != 'false' && isolated
     next if gem == 'railties' && isolated
     next if gem == 'aj:integration' && isolated