diff --git a/CI.lean b/CI.lean
index a4cb570..8d7e579 100644
--- a/CI.lean
+++ b/CI.lean
@@ -16,7 +16,7 @@ jobs:
           curl -sSfL https://github.com/leanprover/elan/releases/download/v4.0.0/elan-x86_64-unknown-linux-gnu.tar.gz | tar xz
           ./elan-init -y --default-toolchain none
           echo \"$HOME/.elan/bin\" >> $GITHUB_PATH
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: run LSpec binary
         run: lake exe lspec
 "
diff --git a/README.md b/README.md
index 3646896..f93d700 100644
--- a/README.md
+++ b/README.md
@@ -173,7 +173,7 @@ jobs:
           curl -sSfL https://github.com/leanprover/elan/releases/download/v4.0.0/elan-x86_64-unknown-linux-gnu.tar.gz | tar xz
           ./elan-init -y --default-toolchain none
           echo "$HOME/.elan/bin" >> $GITHUB_PATH
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: run LSpec binary
         run: lake exe lspec
 ```