diff --git a/include/drivers/auth/mbedtls/mbedtls_config-3.h b/include/drivers/auth/mbedtls/mbedtls_config-3.h
index ba936a3..923fc54 100644
--- a/include/drivers/auth/mbedtls/mbedtls_config-3.h
+++ b/include/drivers/auth/mbedtls/mbedtls_config-3.h
@@ -62,8 +62,12 @@
 #if TF_MBEDTLS_USE_ECDSA
 #define MBEDTLS_ECDSA_C
 #define MBEDTLS_ECP_C
+#if TF_MBEDTLS_KEY_SIZE == 384
+#define MBEDTLS_ECP_DP_SECP384R1_ENABLED
+#else
 #define MBEDTLS_ECP_DP_SECP256R1_ENABLED
 #endif
+#endif
 #if TF_MBEDTLS_USE_RSA
 #define MBEDTLS_RSA_C
 #define MBEDTLS_X509_RSASSA_PSS_SUPPORT