diff --git a/kexgexc.c b/kexgexc.c
index 955bc83..0d07f73 100644
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -37,6 +37,8 @@
 #include <string.h>
 #include <signal.h>
 
+#include "openbsd-compat/openssl-compat.h"
+
 #include "sshkey.h"
 #include "cipher.h"
 #include "digest.h"