diff --git a/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h b/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
index 98f0e367d..7d930427e 100644
--- a/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
+++ b/tf-psa-crypto/drivers/builtin/include/mbedtls/config_adjust_test_accelerators.h
@@ -20,7 +20,7 @@
  * drivers. All the built-in drivers and the transparent test drivers are
  * included in the build by starting from a full configuration (config.py full)
  * and defining PSA_CRYPTO_DRIVER_TEST when building
- * (make -DPSA_CRYPTO_DRIVER_TEST ...).
+ * (make CFLAGS="-DPSA_CRYPTO_DRIVER_TEST ...").
  *
  * The purpose of this header is to declare the transparent test drivers as
  * accelerators just after infering the built-in drivers