diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 65d992d8d..3d517d292 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -961,6 +961,8 @@ static psa_hash_operation_t psa_hash_operation_init(void);
  * \retval #PSA_ERROR_HARDWARE_FAILURE
  * \retval #PSA_ERROR_CORRUPTION_DETECTED
  * \retval #PSA_ERROR_BAD_STATE
+ *         \p operation is either not initialized or is in use
+ * \retval #PSA_ERROR_BAD_STATE
  *         The library has not been previously initialized by psa_crypto_init().
  *         It is implementation-dependent whether a failure to initialize
  *         results in this error code.