diff --git a/appl/kx/kx.c b/appl/kx/kx.c
index 2dbfff8ae..4ba40fd3e 100644
--- a/appl/kx/kx.c
+++ b/appl/kx/kx.c
@@ -221,7 +221,7 @@ childhandler ()
 
   do { 
     pid = waitpid (-1, &status, WNOHANG|WUNTRACED);
-  } while(pid);
+  } while(pid > 0);
   signal (SIGCHLD, childhandler);
 }