diff --git a/config2.h.in b/config2.h.in
index dd5b413b..540d5d79 100644
--- a/config2.h.in
+++ b/config2.h.in
@@ -515,6 +515,9 @@
 /* Define to 1 if you have the <libev/event.h> header file. */
 #mesondefine HAVE_LIBEV_EVENT_H
 
+/* Define to 1 if you have the <libgen.h> header file. */
+#mesondefine HAVE_LIBGEN_H
+
 /* Define to 1 if you have the `nsl' library (-lnsl). */
 #mesondefine HAVE_LIBNSL