diff --git a/top/top.c b/top/top.c
index 60141551..3d390b28 100644
--- a/top/top.c
+++ b/top/top.c
@@ -3386,8 +3386,10 @@ static void summary_show (void) {
       int shift = 0;
 
       /*** hotplug_acclimated ***/
-      if (kb_main_total > 9999999)    { which = N_txt(AMT_megabyte_txt); shift = 10; }
-      if (kb_main_total > 9999999999) { which = N_txt(AMT_gigabyte_txt); shift = 20; }
+      if (kb_main_total > 9999999)
+         { which = N_txt(AMT_megabyte_txt); shift = 10; }
+      if (kb_main_total > 9999999999ull)
+         { which = N_txt(AMT_gigabyte_txt); shift = 20; }
 
       show_special(0, fmtmk(N_unq(MEMORY_lines_fmt)
          , which, mkM(total), mkM(used), mkM(free),  mkM(buffers)