diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 758a514..a3e3f83 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -2191,6 +2191,8 @@
  * Enable parsing and verification of X.509 certificates, CRLs and CSRS
  * signed with RSASSA-PSS (aka PKCS#1 v2.1).
  *
+ * Requires: MBEDTLS_PKCS1_V21
+ *
  * Comment this macro to disallow using RSASSA-PSS in certificates.
  */
 #define MBEDTLS_X509_RSASSA_PSS_SUPPORT