diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 58d7807..c022a61 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3146,6 +3146,7 @@
  * Module:  library/psa_crypto.c
  *
  * Requires: either MBEDTLS_CTR_DRBG_C and MBEDTLS_ENTROPY_C,
+ *           or MBEDTLS_HMAC_DRBG_C and MBEDTLS_ENTROPY_C,
  *           or MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG.
  *
  */