diff --git a/.swift-version b/.swift-version
index 8336407..bf77d54 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-5.1
\ No newline at end of file
+4.2
diff --git a/Package.swift b/Package.swift
index 83a33db..90d07ca 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.1
+// swift-tools-version:4.2
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription