diff --git a/benchmarks/cachespeed/cachespeed_main.c b/benchmarks/cachespeed/cachespeed_main.c
index c8934e437..30bd06eef 100644
--- a/benchmarks/cachespeed/cachespeed_main.c
+++ b/benchmarks/cachespeed/cachespeed_main.c
@@ -141,7 +141,7 @@ static void report_line(size_t bytes, TIME cost)
 
   if (cost == 0)
     {
-      printf(CACHESPEED_PREFIX "%d bytes cost time too small!\n", bytes);
+      printf(CACHESPEED_PREFIX "%zu bytes cost time too small!\n", bytes);
       return;
     }
 
@@ -149,7 +149,7 @@ static void report_line(size_t bytes, TIME cost)
 
   rate = 1.00 * bytes * REPEAT_NUM / cost;
 
-  printf("%d Bytes: %4lf, %4llu, %4llu\n\r",
+  printf("%zu Bytes: %4lf, %4" PRIu64", %4" PRIu64"\n\r",
          bytes, rate, cost / REPEAT_NUM, cost);
 }