diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 4a0bd8331..e45b5d70a 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3592,6 +3592,7 @@ static psa_status_t psa_aead_check_nonce_length( psa_algorithm_t alg,
             break;
 #endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
         default:
+            (void) nonce_length;
             return( PSA_ERROR_NOT_SUPPORTED );
     }