diff --git a/tree.go b/tree.go
index b9caae3..d5e244d 100644
--- a/tree.go
+++ b/tree.go
@@ -112,6 +112,10 @@ func (t Tree) Filter(filter map[string][]string) (Tree, bool) {
 					exclude = true
 				}
 			}
+
+			if negative && !exclude {
+				addFile = true
+			}
 		}
 		if addFile && !exclude {
 			found = true