diff --git a/Sources/AllTests/RxMutableBox.swift b/Sources/AllTests/RxMutableBox.swift
new file mode 120000
index 00000000..34f155ea
--- /dev/null
+++ b/Sources/AllTests/RxMutableBox.swift
@@ -0,0 +1 @@
+../../RxSwift/RxMutableBox.swift
\ No newline at end of file
diff --git a/scripts/package-swift-manager.swift b/scripts/package-swift-manager.swift
index b6723c6f..03b1b6bb 100755
--- a/scripts/package-swift-manager.swift
+++ b/scripts/package-swift-manager.swift
@@ -67,4 +67,4 @@ try packageRelativePath(["RxCocoa/Common", "RxCocoa/OSX", "RxCocoa/RxCocoa.h"],
 try packageRelativePath(["RxBlocking"], targetDirName: "RxBlocking")
 try packageRelativePath(["RxTests"], targetDirName: "RxTests")
 // It doesn't work under `Tests` subpath ¯\_(ツ)_/¯
-try packageRelativePath(["Tests/RxTest.swift", "Tests/Tests", "Tests/RxSwiftTests"], targetDirName: "AllTests")
\ No newline at end of file
+try packageRelativePath(["RxSwift/RxMutableBox.swift", "Tests/RxTest.swift", "Tests/Tests", "Tests/RxSwiftTests"], targetDirName: "AllTests")
\ No newline at end of file