diff --git a/kernel/signal.c b/kernel/signal.c
index 8e19d27..bc972d7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -23,6 +23,7 @@
 #include <linux/ptrace.h>
 #include <linux/signal.h>
 #include <linux/capability.h>
+#include <linux/freezer.h>
 #include <asm/param.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>