diff --git a/R/qsys_multicore.r b/R/qsys_multicore.r
index 7a64ffd..8d3eb8d 100644
--- a/R/qsys_multicore.r
+++ b/R/qsys_multicore.r
@@ -47,10 +47,9 @@ MULTICORE = R6::R6Class("MULTICORE",
         },
 
         children = list(),
-        is_cleaned_up = TRUE, #TODO:
 
         finalize = function(quiet=FALSE) {
-            if (!private$is_cleaned_up) {
+            if (length(private$children) > 0) {
                 private$collect_children(wait=FALSE, timeout=0)
                 running = names(private$children)
                 if (length(running) > 0) {
@@ -60,7 +59,7 @@ MULTICORE = R6::R6Class("MULTICORE",
                                 immediate.=TRUE)
                     tools::pskill(running, tools::SIGKILL)
                 }
-                private$is_cleaned_up = TRUE
+                private$children = list()
             }
         }
     )