diff --git a/include/polarssl/x509_csr.h b/include/polarssl/x509_csr.h
index 8b4892a..af3f226 100644
--- a/include/polarssl/x509_csr.h
+++ b/include/polarssl/x509_csr.h
@@ -67,6 +67,9 @@
     x509_buf sig;
     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
 }
 x509_csr;