diff --git a/common/configure.ac b/common/configure.ac
index fc2f8bf..fabde36 100644
--- a/common/configure.ac
+++ b/common/configure.ac
@@ -87,6 +87,7 @@
 AC_CHECK_HEADERS([sys/select.h])
 
 AC_OUTPUT([Makefile
+	   os/Makefile
 	   rdr/Makefile
 	   network/Makefile
 	   Xregion/Makefile