diff.go | 3 +++

diff --git a/diff.go b/diff.go
index be79911b777e14b1857fe35a74639400adbbdb1a91a80884fcf0640ce71a5d78..181f5c3ee94b6acbe65d9b29786325b881e0d221b7af78d7481638beacbcf832 100644
--- a/diff.go
+++ b/diff.go
@@ -223,6 +223,9 @@ 			ent.mtime = mods[0].mtime
 			ent.size = mods[0].size
 			mods = mods[1:]
 		}
+		if ent.IsDir() {
+			ent.size = 0
+		}
 		entsDirSizer <- ent
 	}
 	for len(adds) > 0 {