diff --git a/source/tools/detect/sched/tasktop/tasktop.c b/source/tools/detect/sched/tasktop/tasktop.c
index 1d225756be39af57522f389510a8146a1702fe14..f4314d67b6206b252ec644d3a39717bcf430b5c1 100644
--- a/source/tools/detect/sched/tasktop/tasktop.c
+++ b/source/tools/detect/sched/tasktop/tasktop.c
@@ -74,7 +74,7 @@ const char argp_program_doc[] =
     "    tasktop -e 10      # limit the d-stack no more than 10, default is "
     "20.\n"
     "    tasktop -H         # output time string, not timestamp."
-    "    tasktop -f a.log   # log to a.log.\n";
+    "    tasktop -f a.log   # log to a.log.\n"
     "    tasktop -e 10      # most record 10 d-task stack.\n";
 
 static const struct argp_option opts[] = {
@@ -1057,7 +1057,8 @@ static void group_by_stack(struct record_t* rec, FILE* dest, int d_num) {
         }
 
         if (!match) {
-            stack[empty_slot++] = s;
+            stack[empty_slot] = s;
+            counter[empty_slot++] = 1;
         }
     }