diff --git a/src/curve25519.c b/src/curve25519.c
index cbef5765..99d7145b 100644
--- a/src/curve25519.c
+++ b/src/curve25519.c
@@ -37,6 +37,7 @@
 #include "libssh/crypto.h"
 #include "libssh/dh.h"
 #include "libssh/pki.h"
+#include "libssh/bignum.h"
 
 /** @internal
  * @brief Starts curve25519-sha256@libssh.org key exchange
diff --git a/src/ecdh.c b/src/ecdh.c
index 0e48c374..e6310b4c 100644
--- a/src/ecdh.c
+++ b/src/ecdh.c
@@ -26,6 +26,7 @@
 #include "libssh/buffer.h"
 #include "libssh/ssh2.h"
 #include "libssh/pki.h"
+#include "libssh/bignum.h"
 
 #ifdef HAVE_ECDH
 #include <openssl/ecdh.h>