diff --git a/include/polarssl/x509_crt.h b/include/polarssl/x509_crt.h
index 4e7bbb7..ee8f9e6 100644
--- a/include/polarssl/x509_crt.h
+++ b/include/polarssl/x509_crt.h
@@ -371,7 +371,7 @@
  *                  (e.g. POLARSSL_MD_SHA1)
  *
  * \param ctx       CRT context to use
- * \param md_ald    MD algorithm to use
+ * \param md_alg    MD algorithm to use
  */
 void x509write_crt_set_md_alg( x509write_cert *ctx, md_type_t md_alg );
 
@@ -467,7 +467,7 @@
  *                        return value to determine where you should start
  *                        using the buffer
  *
- * \param crt       certificate to write away
+ * \param ctx       certificate to write away
  * \param buf       buffer to write to
  * \param size      size of the buffer
  * \param f_rng     RNG function (for signature, see note)
@@ -489,7 +489,7 @@
 /**
  * \brief           Write a built up certificate to a X509 PEM string
  *
- * \param crt       certificate to write away
+ * \param ctx       certificate to write away
  * \param buf       buffer to write to
  * \param size      size of the buffer
  * \param f_rng     RNG function (for signature, see note)