diff --git a/lib/Makefile.in b/lib/Makefile.in
index bef5a8cb5a4..4e51ac6b029 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -17,6 +17,7 @@
 # You should have received a copy of the GNU General Public License
 # along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
+srcdir = @srcdir@
 VPATH = @srcdir@
 
 # Variables substituted by 'configure', and not autogenerated in gnulib.mk,