diff --git a/app/src/main/java/io/nekohasekai/sagernet/fmt/ConfigBuilder.kt b/app/src/main/java/io/nekohasekai/sagernet/fmt/ConfigBuilder.kt
index d38e4c40..4d4d5f6a 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/fmt/ConfigBuilder.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/fmt/ConfigBuilder.kt
@@ -396,7 +396,7 @@ fun buildConfig(
                                     2 -> "yamux"
                                     else -> "h2mux"
                                 }
-                            }
+                            }.asMap()
                         }
                     }
                 }