diff --git a/tools/perf/scripts/perl/wakeup-latency.pl b/tools/perf/scripts/perl/wakeup-latency.pl
index ed58ef284e2..d9143dcec6c 100644
--- a/tools/perf/scripts/perl/wakeup-latency.pl
+++ b/tools/perf/scripts/perl/wakeup-latency.pl
@@ -22,8 +22,8 @@ my %last_wakeup;
 
 my $max_wakeup_latency;
 my $min_wakeup_latency;
-my $total_wakeup_latency;
-my $total_wakeups;
+my $total_wakeup_latency = 0;
+my $total_wakeups = 0;
 
 sub sched::sched_switch
 {
@@ -67,8 +67,12 @@ sub trace_end
 {
     printf("wakeup_latency stats:\n\n");
     print "total_wakeups: $total_wakeups\n";
-    printf("avg_wakeup_latency (ns): %u\n",
-	   avg($total_wakeup_latency, $total_wakeups));
+    if ($total_wakeups) {
+	printf("avg_wakeup_latency (ns): %u\n",
+	       avg($total_wakeup_latency, $total_wakeups));
+    } else {
+	printf("avg_wakeup_latency (ns): N/A\n");
+    }
     printf("min_wakeup_latency (ns): %u\n", $min_wakeup_latency);
     printf("max_wakeup_latency (ns): %u\n", $max_wakeup_latency);