diff --git a/cmd/mbf/main.go b/cmd/mbf/main.go
index 8047e0c4..07ce8f0e 100644
--- a/cmd/mbf/main.go
+++ b/cmd/mbf/main.go
@@ -101,6 +101,7 @@ func main() {
 		flagLTO   bool
 		flagPT    bool
 		flagDry   bool
+		flagPath  string
 
 		flagSourcePath    string
 		flagCrossOverride int
@@ -122,6 +123,8 @@ func main() {
 		if cm.base == "" {
 			cm.base = "cache"
 		}
+		cm.mirror = os.ExpandEnv(cm.mirror)
+		azaleaPath := os.ExpandEnv(flagPath)
 
 		addr.Net = "unix"
 		addr.Name = os.ExpandEnv(addr.Name)
@@ -159,6 +162,17 @@ func main() {
 			}
 		}
 
+		if azaleaPath != "" {
+			var root *os.Root
+			if a, err := check.NewAbs(azaleaPath); err != nil {
+				return err
+			} else if root, err = os.OpenRoot(a.String()); err != nil {
+				return err
+			} else if err = rosa.Native().RegisterFS(root.FS()); err != nil {
+				return err
+			}
+		}
+
 		return nil
 	}).Flag(
 		&flagQuiet,
@@ -231,6 +245,10 @@ func main() {
 		&flagSourcePath,
 		"source", command.StringFlag(""),
 		"Override hakurei source tree",
+	).Flag(
+		&flagPath,
+		"p", command.StringFlag("$AZALEA_PATH"),
+		"Load additional azalea files",
 	)
 
 	c.NewCommand(