diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index 3522818..07be2b9 100644
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -1300,7 +1300,7 @@
                             const uint8_t *input,
                             size_t input_length,
                             const uint8_t *mac,
-                            const size_t mac_length);
+                            size_t mac_length);
 
 /** The type of the state data structure for multipart MAC operations.
  *