diff --git a/src/opt/untk/module.make b/src/opt/untk/module.make
index 35a9eac9f..25af35c41 100755
--- a/src/opt/untk/module.make
+++ b/src/opt/untk/module.make
@@ -1,6 +1,3 @@
 SRC += src/opt/untk/NtkCmd.cpp \
-       src/opt/untk/NtkCmd.h \
        src/opt/untk/Netlist.cpp \
-       src/opt/untk/Netlist.h \
-       src/opt/untk/NtkNtk.cpp \
-       src/opt/untk/NtkNtk.h
+       src/opt/untk/NtkNtk.cpp
\ No newline at end of file
diff --git a/src/opt/util/module.make b/src/opt/util/module.make
index 45e46c251..f939ff08c 100755
--- a/src/opt/util/module.make
+++ b/src/opt/util/module.make
@@ -1,2 +1 @@
-SRC += src/opt/util/util.cpp \
-       src/opt/util/util.h
+SRC += src/opt/util/util.cpp
diff --git a/src/opt/util/util.cpp b/src/opt/util/util.cpp
index d5f698337..df5de2fd8 100644
--- a/src/opt/util/util.cpp
+++ b/src/opt/util/util.cpp
@@ -9,8 +9,6 @@
 #include <csignal>
 #include <unistd.h>
 
-#include "util.h"
-
 #ifdef __linux__
 #include <sys/prctl.h>
 #elif defined(__APPLE__)
@@ -22,6 +20,8 @@
 #include <sys/time.h>
 #endif
 
+#include "util.h"
+
 ABC_NAMESPACE_IMPL_START
 
 using namespace std;
@@ -75,8 +75,6 @@ void kill_on_parent_death(int sig)
     }
 }
 
-/*
-
 #elif defined(__APPLE__)
 
 template <typename Func>
@@ -125,8 +123,6 @@ void kill_on_parent_death(int sig)
   monitor_thread.detach();
 }
 
-*/
-
 #else // neither linux or OS X
 
 void kill_on_parent_death(int sig)