--- a/src/gmp/mpn/generic/addsub_n.c
+++ b/src/gmp/mpn/generic/addsub_n.c
@@ -129,8 +129,6 @@
 #include <stdio.h>
 #include "timing.h"
 
-long cputime ();
-
 int
 main (int argc, char **argv)
 {