diff --git a/unix/configure.ac b/unix/configure.ac
index c0c2adf..8c9d37d 100644
--- a/unix/configure.ac
+++ b/unix/configure.ac
@@ -5,6 +5,8 @@
 
 AC_SUBST([COMMON_DIR], ['$(top_srcdir)/../common'])
 
+AC_CONFIG_SUBDIRS([../common])
+
 dnl Checks for programs.
 AC_PROG_CC
 AC_PROG_CXX