diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index eb75935..5c07b91 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -42,6 +42,7 @@
 #include "mbedtls/private_access.h"
 
 #include "mbedtls/build_info.h"
+#include "mbedtls/platform_util.h"
 
 #include <stddef.h>
 #include <stdint.h>