diff --git a/libmapper/app.c b/libmapper/app.c
index f0d6b03..887d02f 100644
--- a/libmapper/app.c
+++ b/libmapper/app.c
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include "config.h"
 #include <stdlib.h>
 #include <stdio.h>
 #include <systemd/sd-bus.h>