diff --git a/3rdparty/p256-m/p256-m_driver_entrypoints.c b/3rdparty/p256-m/p256-m_driver_entrypoints.c
index dab8bed9e4..f8eeb6767d 100644
--- a/3rdparty/p256-m/p256-m_driver_entrypoints.c
+++ b/3rdparty/p256-m/p256-m_driver_entrypoints.c
@@ -25,6 +25,7 @@
 #include <stddef.h>
 #include <string.h>
 #include "psa_crypto_driver_wrappers.h"
+#include <stddef.h>
 
 #if defined(MBEDTLS_PSA_P256M_DRIVER_ENABLED)