diff --git a/include/polarssl/x509_crt.h b/include/polarssl/x509_crt.h
index 0081d36..09cc982 100644
--- a/include/polarssl/x509_crt.h
+++ b/include/polarssl/x509_crt.h
@@ -93,6 +93,9 @@
     x509_buf sig;               /**< Signature: hash of the tbs part signed with the private key. */
     md_type_t sig_md;           /**< Internal representation of the MD algorithm of the signature algorithm, e.g. POLARSSL_MD_SHA256 */
     pk_type_t sig_pk            /**< Internal representation of the Public Key algorithm of the signature algorithm, e.g. POLARSSL_PK_RSA */;
+#if defined(POLARSSL_RSASSA_PSS_CERTIFICATES)
+    x509_buf sig_params;        /**< Parameters for the signature algorithm */
+#endif
 
     struct _x509_crt *next;     /**< Next certificate in the CA-chain. */
 }