diff --git a/runtime/track_memory_map_demo.c b/runtime/track_memory_map_demo.c
index 3809bdc78..8a3abfc22 100644
--- a/runtime/track_memory_map_demo.c
+++ b/runtime/track_memory_map_demo.c
@@ -35,7 +35,7 @@ pid_t spawn_with_tracker(char *const *argv) {
   /* wait to get hold of the tracee */
   int status;
   pid_t ret_pid;
-  while (ret_pid = waitpid(child_pid, &status, 0) == 0) {
+  while ((ret_pid = waitpid(child_pid, &status, 0)) == 0) {
     if (ret_pid < 0) {
       perror("waitpid");
       return -1;