diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index adb18ab..e8d7d88 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -610,6 +610,10 @@
 #endif
 
 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+    transform->psa_mac_enc = MBEDTLS_SVC_KEY_ID_INIT;
+    transform->psa_mac_dec = MBEDTLS_SVC_KEY_ID_INIT;
+#endif
     mbedtls_md_init( &transform->md_ctx_enc );
     mbedtls_md_init( &transform->md_ctx_dec );
 #endif