diff --git a/driver/LKM/include/smith_hook.h b/driver/LKM/include/smith_hook.h
index fc3b5df49..7df635a03 100644
--- a/driver/LKM/include/smith_hook.h
+++ b/driver/LKM/include/smith_hook.h
@@ -14,6 +14,7 @@
 #include "kprobe.h"
 #include "util.h"
 #include "filter.h"
+#include "memcache.h"
 #include "struct_wrap.h"
 
 #include <linux/usb.h>
diff --git a/driver/LKM/include/util.h b/driver/LKM/include/util.h
index 44cf98805..d6ef35a4d 100644
--- a/driver/LKM/include/util.h
+++ b/driver/LKM/include/util.h
@@ -28,6 +28,20 @@
 
 static unsigned int ROOT_PID_NS_INUM;
 
+/*
+ * macro definitions for legacy kernels
+ */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
+#define __ARG_PLACEHOLDER_1 0,
+#define config_enabled(cfg) _config_enabled(cfg)
+#define _config_enabled(value) __config_enabled(__ARG_PLACEHOLDER_##value)
+#define __config_enabled(arg1_or_junk) ___config_enabled(arg1_or_junk 1, 0)
+#define ___config_enabled(__ignored, val, ...) val
+#define IS_ENABLED(option) \
+        (config_enabled(option) || config_enabled(option##_MODULE))
+#endif
+
 /*
  * wrapper of kernel memory allocation routines
  */
diff --git a/driver/LKM/src/anti_rootkit.c b/driver/LKM/src/anti_rootkit.c
index 39652915e..7539d5829 100644
--- a/driver/LKM/src/anti_rootkit.c
+++ b/driver/LKM/src/anti_rootkit.c
@@ -12,11 +12,10 @@
 #if ANTI_ROOTKIT_CHECK
 
 #include <linux/kthread.h>
+#include "../include/util.h"
 #include "../include/trace.h"
-#include "../include/struct_wrap.h"
 #include "../include/kprobe.h"
 #include "../include/anti_rootkit.h"
-#include "../include/util.h"
 
 #define CREATE_PRINT_EVENT
 #include "../include/anti_rootkit_print.h"
diff --git a/driver/LKM/src/trace.c b/driver/LKM/src/trace.c
index 567615509..038cd6801 100644
--- a/driver/LKM/src/trace.c
+++ b/driver/LKM/src/trace.c
@@ -9,9 +9,10 @@
 #include <linux/proc_fs.h>
 #include <linux/slab.h>
 #include <linux/version.h>
+
+#include "../include/util.h"
 #include "../include/trace.h"
 #include "../include/kprobe.h"
-#include "../include/util.h"
 
 #define PROC_ENDPOINT	"elkeid-endpoint"