diff --git a/.github/workflows/soundness.yml b/.github/workflows/soundness.yml
index 6b962a9..0de2761 100644
--- a/.github/workflows/soundness.yml
+++ b/.github/workflows/soundness.yml
@@ -82,6 +82,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -102,6 +103,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run documentation check
         run: |
           apt-get -qq update && apt-get -qq -y install curl yq
@@ -117,6 +119,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run unacceptable language check
         env:
           UNACCEPTABLE_WORD_LIST: ${{ inputs.unacceptable_language_check_word_list}}
@@ -132,6 +135,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run license header check
         env:
           PROJECT_NAME: ${{ inputs.license_header_check_project_name }}
@@ -147,6 +151,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run broken symlinks check
         run: curl -s https://raw.githubusercontent.com/swiftlang/github-workflows/refs/heads/main/.github/workflows/scripts/check-broken-symlinks.sh | bash
 
@@ -162,6 +167,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -182,6 +188,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Mark the workspace as safe
         # https://github.com/actions/checkout/issues/766
         run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
@@ -200,6 +207,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run yamllint
         run: |
           which yamllint >/dev/null || ( apt-get update && apt-get install -y yamllint )
@@ -215,6 +223,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false
+          submodules: true
       - name: Run flake8
         run: |
           pip3 install flake8 flake8-import-order