diff --git a/vfs/vfs.go b/vfs/vfs.go
index 58e7630b1..ccd10265c 100644
--- a/vfs/vfs.go
+++ b/vfs/vfs.go
@@ -510,6 +510,15 @@ func (vfs *VFS) Statfs() (total, used, free int64) {
 		if u.Used != nil {
 			used = *u.Used
 		}
+		if total < 0 && free >= 0 && used >= 0 {
+			total = free + used
+		}
+		if free < 0 && total >= 0 && used >= 0 {
+			free = total - used
+		}
+		if used < 0 && total >= 0 && free >= 0 {
+			used = total - free
+		}
 	}
 	return
 }