diff --git a/core/sems.cpp b/core/sems.cpp
index 7b7f406f..6f5d578f 100644
--- a/core/sems.cpp
+++ b/core/sems.cpp
@@ -92,7 +92,6 @@ static void sig_usr_un(int signo)
   WARN("Signal %d received.\n", signo);
     
   if (!main_pid || (main_pid == getpid())) {
-    unlink(pid_file.c_str());
 
     static AmMutex            clean_up_mut;
     static AmCondition<bool>  need_clean(true);
@@ -118,6 +117,8 @@ static void sig_usr_un(int signo)
 
     INFO("Finished.\n");
 
+    unlink(pid_file.c_str());
+
     exit(0);
   }