diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7949d19..eb8b30a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,12 +6,11 @@ on:
   pull_request:
     branches: [ "master" ]
 
-env:
-  DEVELOPER_DIR: /Applications/Xcode_16.0.app/Contents/Developer
-
 jobs:
   build:
     runs-on: macos-latest
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_16.0.app/Contents/Developer
     steps:
     - uses: actions/checkout@v4
       with:
@@ -29,3 +28,13 @@ jobs:
       with:
         fail_ci_if_error: true
         verbose: true
+  build-swift-5-10:
+    runs-on: macos-14
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    - name: Check Swift version
+      run: swift --version
+    - name: Build
+      run: swift build
diff --git a/.swift-version b/.swift-version
index 5049538..f0933d4 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-6.0
\ No newline at end of file
+5.10
\ No newline at end of file
diff --git a/Package@swift-5.10.swift b/Package@swift-5.10.swift
new file mode 100644
index 0000000..d0747dc
--- /dev/null
+++ b/Package@swift-5.10.swift
@@ -0,0 +1,18 @@
+// swift-tools-version: 5.10
+
+import PackageDescription
+
+let package = Package(
+    name: "swift-environment-decoder",
+    products: [
+        .library(
+            name: "EnvironmentDecoder",
+            targets: ["EnvironmentDecoder"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
+    ],
+    targets: [
+        .target(
+            name: "EnvironmentDecoder"),
+    ])