diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index f728055..d649b24 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -42,6 +42,8 @@ jobs:
           GROUP: ${{ matrix.group }}
           JULIA_CMDSTAN_HOME: "/home/runner/cmdstan-2.29.2/"
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           file: lcov.info
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: true
diff --git a/.github/workflows/Documentation.yml b/.github/workflows/Documentation.yml
index 4371b13..412c4c5 100644
--- a/.github/workflows/Documentation.yml
+++ b/.github/workflows/Documentation.yml
@@ -25,6 +25,8 @@ jobs:
           JULIA_CMDSTAN_HOME: "/home/runner/cmdstan-2.29.2/"
         run: julia --project=docs/ --code-coverage=user docs/make.jl
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v4
         with:
           file: lcov.info
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: true