diff --git a/library/entropy.c b/library/entropy.c
index af78acc..e9a7ae6 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -31,6 +31,8 @@
 #include "mbedtls/entropy_poll.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/error.h"
+#include "mbedtls/sha256.h"
+#include "mbedtls/sha512.h"
 
 #include <string.h>