diff --git a/top.c b/top.c
index 6d4a7cc..8871824 100644
--- a/top.c
+++ b/top.c
@@ -2991,6 +2991,9 @@ static proc_t **summary_show (void)
       );
       Msg_row += 1;
 
+      smp_num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+      if(smp_num_cpus<1) smp_num_cpus=1;
+      Cpu_tot = smp_num_cpus;
       smpcpu = cpus_refresh(smpcpu);
 
       if (CHKw(Curwin, View_CPUSUM)) {