diff --git a/openvpn/mbedtls/util/selftest.hpp b/openvpn/mbedtls/util/selftest.hpp
index a3858686..ecb5c7ca 100644
--- a/openvpn/mbedtls/util/selftest.hpp
+++ b/openvpn/mbedtls/util/selftest.hpp
@@ -26,9 +26,11 @@
 
 #include <sstream>
 
+#include <mbedtls/bignum.h>
 #include <mbedtls/config.h>
 #include <mbedtls/cipher.h>
 #include <mbedtls/aes.h>
+#include <mbedtls/sha1.h>
 #include <mbedtls/sha256.h>
 #include <mbedtls/sha512.h>