diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index b1c1abb..089484f 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -1064,6 +1064,7 @@
 
 psa_status_t psa_cipher_finish(psa_cipher_operation_t *operation,
                                uint8_t *output,
+                               size_t output_size,
                                size_t *output_length);
 
 psa_status_t psa_cipher_abort(psa_cipher_operation_t *operation);