diff --git a/.travis.yml b/.travis.yml
index e26fedc7ae2093..9458a12f6e41e3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -57,6 +57,10 @@ jobs:
       install:
         - npm ci
       script:
+        # It's not necessary to run the full build, since Jest can interpret
+        # source files with `babel-jest`. Some packages have their own custom
+        # build tasks, however. These must be run.
+        - npx lerna run build
         - npm run test-unit -- --ci --maxWorkers=2 --cacheDirectory="$HOME/.jest-cache"
 
     - name: PHP unit tests (Docker)