diff --git a/tool/travis.sh b/tool/travis.sh
index a3f3082..b450e6e 100755
--- a/tool/travis.sh
+++ b/tool/travis.sh
@@ -15,7 +15,7 @@
   test/all.dart
 
 # Run the tests.
-dart -c test/all.dart
+dart --enable-asserts test/all.dart
 
 # Measure the size of the compiled JS, for the dart:html version of the library.
 dart tool/grind.dart build