diff --git a/kmod/src/item.c b/kmod/src/item.c
index 68895042..b3e9d8f5 100644
--- a/kmod/src/item.c
+++ b/kmod/src/item.c
@@ -1488,9 +1488,12 @@ int scoutfs_item_dirty_seg(struct super_block *sb, struct scoutfs_segment *seg)
 	struct item_cache *cac = sbi->item_cache;
 	struct cached_item *item = NULL;
 	struct cached_item *del;
+	unsigned long flags;
 	u32 key_bytes;
 	u32 nr_items;
 
+	spin_lock_irqsave(&cac->lock, flags);
+
 	count_seg_items(cac, &nr_items, &key_bytes);
 
 	/* remember nr_items is passed to _first_item */
@@ -1522,6 +1525,8 @@ int scoutfs_item_dirty_seg(struct super_block *sb, struct scoutfs_segment *seg)
 		nr_items--;
 	}
 
+	spin_unlock_irqrestore(&cac->lock, flags);
+
 	return 0;
 }