diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index f39d1eb..f132f7e 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -446,6 +446,9 @@
  * \note This is an experimental extension to the interface. It may change
  *       in future versions of the library.
  *
+ * \note Due to an implementation limitation, domain parameters are ignored
+ *       for keys that are managed by a driver.
+ *
  * \param[in,out] attributes    Attribute structure where the specified domain
  *                              parameters will be stored.
  *                              If this function fails, the content of
@@ -476,6 +479,9 @@
  * \note This is an experimental extension to the interface. It may change
  *       in future versions of the library.
  *
+ * \note Due to an implementation limitation, domain parameters are not
+ *       supported with keys that are managed by a driver.
+ *
  * \param[in] attributes        The key attribute structure to query.
  * \param[out] data             On success, the key domain parameters.
  * \param data_size             Size of the \p data buffer in bytes.
@@ -488,6 +494,8 @@
  *
  * \retval #PSA_SUCCESS \emptydescription
  * \retval #PSA_ERROR_BUFFER_TOO_SMALL \emptydescription
+ * \retval #PSA_ERROR_NOT_SUPPORTED
+ *         The key is managed by a driver.
  */
 psa_status_t psa_get_key_domain_parameters(
     const psa_key_attributes_t *attributes,
diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index 1eb2463..5e52ffd 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -259,7 +259,7 @@
      * - domain_parameters_size == SIZE_MAX && domain_parameters == NULL:
      *   Access to domain parameters is not supported for this key.
      *   This is a hack which should not exist, intended for keys managed
-     *   by a driver that doesn't support domain parameters.
+     *   by a driver, because drivers don't support domain parameters.
      * - domain_parameters_size == 0 && domain_parameters == NULL:
      *   The domain parameters are empty.
      * - domain_parameters_size > 0 &&