diff --git a/fs/internal.h b/fs/internal.h
index e325b4f..b262320 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -35,6 +35,11 @@
 #endif
 
 /*
+ * buffer.c
+ */
+extern void guard_bio_eod(int rw, struct bio *bio);
+
+/*
  * char_dev.c
  */
 extern void __init chrdev_init(void);