diff --git a/drivers/auth/mbedtls/mbedtls_common.mk b/drivers/auth/mbedtls/mbedtls_common.mk
index 54c819c..0a4775d 100644
--- a/drivers/auth/mbedtls/mbedtls_common.mk
+++ b/drivers/auth/mbedtls/mbedtls_common.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2015-2021, Arm Limited. All rights reserved.
+# Copyright (c) 2015-2022, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -16,7 +16,7 @@
 MBEDTLS_INC		=	-I${MBEDTLS_DIR}/include
 
 # Specify mbed TLS configuration file
-MBEDTLS_CONFIG_FILE	:=	"<drivers/auth/mbedtls/mbedtls_config.h>"
+MBEDTLS_CONFIG_FILE	?=	"<drivers/auth/mbedtls/mbedtls_config.h>"
 $(eval $(call add_define,MBEDTLS_CONFIG_FILE))
 
 MBEDTLS_SOURCES	+=		drivers/auth/mbedtls/mbedtls_common.c