diff --git a/lib/yyerror.c b/lib/yyerror.c
index 7db92bc4..5eb339fa 100644
--- a/lib/yyerror.c
+++ b/lib/yyerror.c
@@ -17,6 +17,7 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+#include <config.h>
 #include <stdio.h>
 
 int yyerror (char const *);