diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 3e2bac5..c9e7072 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -6,16 +6,16 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: norio-nomura/action-swiftlint@3.2.1
   macos-test:
     strategy:
       matrix:
         swift-version:
-          - "5.7"
+          - "5.9"
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: swift-actions/setup-swift@v1
         with:
           swift-version: ${{ matrix.swift-version }}
@@ -24,6 +24,8 @@ jobs:
     strategy:
       matrix:
         swift-version:
+          - "5.9"
+          - "5.8"
           - "5.7"
           - "5.6"
           - "5.5"
@@ -33,12 +35,15 @@ jobs:
           - "5.1"
           - "5.0"
     runs-on: ubuntu-latest
-    container: swift:${{ matrix.swift-version }}
+    container:
+      image: swift:${{ matrix.swift-version }}
+      volumes:
+        - /lib/x86_64-linux-gnu/libc.so.6:/lib/x86_64-linux-gnu/libc.so.6
     steps:
       - uses: actions/checkout@v3
       - run: swift test
   ios-build:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: xcodebuild -scheme geodesic -destination 'platform=iOS Simulator,name=iPhone 13'
diff --git a/README.md b/README.md
index 5d35d93..fad1e06 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # geodesic
 
-[![Swift Version](https://img.shields.io/badge/swift-5.7-blue.svg)](https://swift.org)
+[![Swift Version](https://img.shields.io/badge/swift-5.9-blue.svg)](https://swift.org)
 ![Platform](https://img.shields.io/badge/platform-macOS|linux--64-lightgray.svg)
 ![Build](https://github.com/dastrobu/geodesic/actions/workflows/ci.yaml/badge.svg)
 [![GeographicLib Version](https://img.shields.io/badge/GeographicLib-2.1-blue.svg)](https://github.com/geographiclib/geographiclib-c/releases/tag/v2.1)