diff --git a/crypto/ecdh/ech_ossl.c b/crypto/ecdh/ech_ossl.c
index b00c6c431a7fba16d5ed05b0e28afbbcf8068bec..076eb2ea1f6bc3012d6904925c491347107ba8b3 100644
--- a/crypto/ecdh/ech_ossl.c
+++ b/crypto/ecdh/ech_ossl.c
@@ -70,6 +70,8 @@
 
 #include <limits.h>
 
+#include "cryptlib.h"
+
 #include <openssl/ecdh.h>
 #include <openssl/err.h>
 #include <openssl/sha.h>