diff --git a/include/psa/crypto_platform.h b/include/psa/crypto_platform.h
index 8acf22c..d60b773 100644
--- a/include/psa/crypto_platform.h
+++ b/include/psa/crypto_platform.h
@@ -32,6 +32,7 @@
 
 #ifndef PSA_CRYPTO_PLATFORM_H
 #define PSA_CRYPTO_PLATFORM_H
+#include "mbedtls/private_access.h"
 
 /* Include the Mbed TLS configuration file, the way Mbed TLS does it
  * in each of its header files. */
@@ -92,7 +93,7 @@
  * are expected to replace it with a custom definition.
  */
 typedef struct {
-    uintptr_t opaque[2];
+    uintptr_t MBEDTLS_PRIVATE(opaque)[2];
 } mbedtls_psa_external_random_context_t;
 #endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */