1 files changed, 1 insertions, 0 deletions
diff --git a/ext/extmk.rb b/ext/extmk.rb
index ac396a0d80..53790e4f25 100644
--- a/ext/extmk.rb
+++ b/ext/extmk.rb
@@ -324,6 +324,7 @@ else
   $ruby = '$(topdir)/miniruby' + EXEEXT
 end
 $ruby << " -I'$(topdir)' -I'$(hdrdir)/lib'"
+$ruby << " -I'#{$extout}'" if $extout
 $config_h = '$(topdir)/config.h'
 
 MTIMES = [__FILE__, 'rbconfig.rb', srcdir+'/lib/mkmf.rb'].collect {|f| File.mtime(f)}