diff --git a/ChangeLog b/ChangeLog
index c055aa816c..0f513e3902 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul  1 13:00:54 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* common.mk (test-knownbug): ignore known bugs.
+
 Thu Jul  1 12:59:14 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* test/rubygems/test_gem_activation.rb: comment out a test for WONTFIX
diff --git a/common.mk b/common.mk
index d899b3c3dd..3582c70aa1 100644
--- a/common.mk
+++ b/common.mk
@@ -425,10 +425,11 @@ no-test-sample: PHONY
 yes-test-sample: PHONY
 	@$(RUNRUBY) $(srcdir)/tool/rubytest.rb
 
+test-knownbugs: test-knownbug
 test-knownbug: miniruby$(EXEEXT) $(PROGRAM) $(RBCONFIG) $(TEST_RUNNABLE)-test-knownbug
 no-test-knownbug: PHONY
 yes-test-knownbug: PHONY
-	$(RUNRUBY) "$(srcdir)/bootstraptest/runner.rb" --ruby="$(PROGRAM)" $(OPTS) $(srcdir)/KNOWNBUGS.rb
+	-$(RUNRUBY) "$(srcdir)/bootstraptest/runner.rb" --ruby="$(PROGRAM)" $(OPTS) $(srcdir)/KNOWNBUGS.rb
 
 test: test-sample btest-ruby test-knownbug