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