diff --git a/test/mkmf/base.rb b/test/mkmf/base.rb

index 1b5b89e..8c19b07 100644

--- a/test/mkmf/base.rb

+++ b/test/mkmf/base.rb

@@ -6,6 +6,7 @@ $extout = '$(topdir)/'+RbConfig::CONFIG["EXTOUT"]

 RbConfig::CONFIG['topdir'] = CONFIG['topdir'] = File.expand_path(CONFIG['topdir'])

 RbConfig::CONFIG["extout"] = CONFIG["extout"] = $extout

 $INCFLAGS << " -I."

+$LDFLAGS << " -L$(topdir)"

 $extout_prefix = "$(extout)$(target_prefix)/"

 class TestMkmf < Test::Unit::TestCase