diff --git a/.travis.yml b/.travis.yml
index 2760c00..04b3dd1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,10 +3,6 @@
 dart:
   - stable
   - dev
-  - 1.22.1
-  - 1.21.1
-  - 1.20.1
-  - 1.19.1
 dart_task:
   - test: -p vm
   - test: -p firefox
@@ -14,6 +10,11 @@
     install_dartium: true
   - dartfmt
   - dartanalyzer
+
+# Only building master means that we don't run two builds for each pull request.
+branches:
+  only: [master]
+
 cache:
   directories:
     - $HOME/.pub-cache