diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d9062f5..2404b59 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -24,6 +24,7 @@
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
 #include <linux/sysctl.h>
+#include <linux/slab.h>
 #include <linux/ctype.h>
 #include <linux/list.h>
 #include <linux/hash.h>