diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
index 0b8b32b..bb2c52f 100644
--- a/include/linux/time_namespace.h
+++ b/include/linux/time_namespace.h
@@ -12,6 +12,7 @@
 struct user_namespace;
 extern struct user_namespace init_user_ns;
 
+struct seq_file;
 struct vm_area_struct;
 
 struct timens_offsets {