diff --git a/bootstraptest/test_knownbug.rb b/bootstraptest/test_knownbug.rb
index b97a08d928..91e3cd5e48 100644
--- a/bootstraptest/test_knownbug.rb
+++ b/bootstraptest/test_knownbug.rb
@@ -3,3 +3,9 @@
 # So all tests will cause failure.
 #
 
+assert_normal_exit %{
+  def foo(&block)
+    yield if block
+  end
+  foo(&:bar)
+}, '[ruby-core:14279]'