diff --git a/ChangeLog b/ChangeLog
index 4c5e9b5a9d..43c50b7267 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Dec  6 22:55:10 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* common.mk (test-build): test for build process.
+
 Mon Dec  6 22:47:15 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/optparse.rb (OptionParser#candidate): skip separators.
diff --git a/common.mk b/common.mk
index c45c3e1f71..62da9aa39e 100644
--- a/common.mk
+++ b/common.mk
@@ -467,6 +467,10 @@ no-test-all: PHONY
 yes-test-all: PHONY
 	$(RUNRUBY) "$(srcdir)/test/runner.rb" $(TESTS)
 
+TESTS_BUILD = mkmf
+test-build: PHONY
+	$(MINIRUBY) -I"$(srcdir)/lib" "$(srcdir)/test/runner.rb" $(TESTS_BUILD)
+
 test-ruby: $(TEST_RUNNABLE)-test-ruby
 no-test-ruby: PHONY
 yes-test-ruby: PHONY
diff --git a/test/runner.rb b/test/runner.rb
index b96081e7e2..e19ed82562 100644
--- a/test/runner.rb
+++ b/test/runner.rb
@@ -1,5 +1,4 @@
 require 'rbconfig'
-exit if CROSS_COMPILING
 
 require 'test/unit'