diff --git a/build.yaml b/build.yaml
index d0eb07b5..71acee0e 100644
--- a/build.yaml
+++ b/build.yaml
@@ -10,7 +10,7 @@ targets:
           # List any dart2js specific args here, or omit it.
           dart2js_args:
             # Omit type checks
-            - -O3
+            - -O2
             # Generate CSP-compliant code since it will be used most often in prod
             - --csp
             # Disable minification for easier test/example debugging