diff --git a/bootstraptest/test_insns.rb b/bootstraptest/test_insns.rb
index 1747941cf0..73a9d501f1 100644
--- a/bootstraptest/test_insns.rb
+++ b/bootstraptest/test_insns.rb
@@ -202,6 +202,7 @@ tests = [
   },
 
   [ 'opt_str_freeze', %q{ 'true'.freeze }, ],
+  [ 'opt_nil_p',      %q{ nil.nil? }, ],
   [ 'opt_str_uminus', %q{ -'true' }, ],
   [ 'opt_str_freeze', <<-'},', ], # {
     class String