diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d7ee9bc..7603f03 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,7 +19,7 @@ jobs:
       CARGO_TERM_COLOR: always
       RUST_BACKTRACE: full
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
           submodules: "true"
diff --git a/.gitmodules b/.gitmodules
index ed8598b..72bdf71 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,4 +1,4 @@
 [submodule "cdevents-spec"]
 	path = cdevents-spec
-	url = git@github.com:cdevents/spec.git
+	url = https://github.com/cdevents/spec.git
 	branch = spec-v0.3
diff --git a/cdevents-spec b/cdevents-spec
new file mode 160000
index 0000000..2b63793
--- /dev/null
+++ b/cdevents-spec
@@ -0,0 +1 @@
+Subproject commit 2b63793165fa609d3a3b954ce71957209e79475e