diff --git a/libssh/kex.c b/libssh/kex.c
index 17c27460..9d3b1701 100644
--- a/libssh/kex.c
+++ b/libssh/kex.c
@@ -41,6 +41,7 @@
 #include "libssh/keys.h"
 #include "libssh/dh.h"
 #include "libssh/kex.h"
+#include "libssh/string.h"
 
 #ifdef HAVE_LIBGCRYPT
 #define BLOWFISH "blowfish-cbc,"
diff --git a/libssh/keys.c b/libssh/keys.c
index 09fc64c1..535c3783 100644
--- a/libssh/keys.c
+++ b/libssh/keys.c
@@ -36,6 +36,7 @@
 #include "libssh/keys.h"
 #include "libssh/dh.h"
 #include "libssh/messages.h"
+#include "libssh/string.h"
 
 /**
  * @addtogroup libssh_auth