diff --git a/sandboxed_api/sandbox2/monitor_base.cc b/sandboxed_api/sandbox2/monitor_base.cc
index e2c4ccf..ed187e7 100644
--- a/sandboxed_api/sandbox2/monitor_base.cc
+++ b/sandboxed_api/sandbox2/monitor_base.cc
@@ -206,7 +206,7 @@ void MonitorBase::Launch() {
 
   process_ = *std::move(process);
 
-  if (process_.main_pid <= 0 || (should_have_init && process_.main_pid <= 0)) {
+  if (process_.main_pid <= 0 || (should_have_init && process_.init_pid <= 0)) {
     SetExitStatusCode(Result::SETUP_ERROR, Result::FAILED_SUBPROCESS);
     return;
   }