diff --git a/kmod/src/block.h b/kmod/src/block.h
index bd1c2e57..aaa85f8e 100644
--- a/kmod/src/block.h
+++ b/kmod/src/block.h
@@ -1,6 +1,8 @@
 #ifndef _SCOUTFS_BLOCK_H_
 #define _SCOUTFS_BLOCK_H_
 
+struct scoutfs_alloc;
+
 struct scoutfs_block_writer {
 	spinlock_t lock;
 	struct list_head dirty_list;