diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 513d96d..c0ad10d 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -334,7 +334,7 @@
 
     return( ecdsa_write_signature( (ecdsa_context *) ctx,
                 hash, hash_len, sig, sig_len, f_rng, p_rng ) );
-#endif
+#endif /* POLARSSL_ECDSA_DETERMINISTIC */
 }
 
 static void *ecdsa_alloc_wrap( void )