diff --git a/.travis.yml b/.travis.yml
index 36690d048b..af90804269 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -44,7 +44,7 @@ before_script:
   - "cp -pr config.status .ext/include config_2nd"
   - "diff -ru config_1st config_2nd"
   - "make touch-unicode-files"
-  - "make after-update BASERUBY=ruby UNICODE_FILES=."
+  - "make after-update BASERUBY=ruby BOOTSTRAPRUBY='$(BASERUBY)' MINIRUBY='$(BASERUBY)' UNICODE_FILES=. PREP= CC=false"
   - "make -s $JOBS"
   - "make update-rubyspec"
   - "requests="