diff --git a/.github/actions/check-english-usage/check-english-usage.sh b/.github/actions/check-english-usage/check-english-usage.sh
index 6e5f2ea6..5fa7c0a9 100755
--- a/.github/actions/check-english-usage/check-english-usage.sh
+++ b/.github/actions/check-english-usage/check-english-usage.sh
@@ -35,13 +35,13 @@ function main() {
       filter="git ls-files -z"
       ;;
     "staged-changes")
-      filter="git diff --diff-filter=ACMRT --name-only --cached -z"
+      filter="git diff --diff-filter=ACMRT --name-only --cached --ignore-submodules=all -z"
       ;;
     "working-tree-changes")
-      filter="git diff --diff-filter=ACMRT --name-only -z"
+      filter="git diff --diff-filter=ACMRT --name-only --ignore-submodules=all -z"
       ;;
     "branch")
-      filter="git diff --diff-filter=ACMRT --name-only -z ${BRANCH_NAME:-origin/main}"
+      filter="git diff --diff-filter=ACMRT --name-only --ignore-submodules=all -z ${BRANCH_NAME:-origin/main}"
       ;;
     *)
       echo "Unrecognised check mode: $check" >&2 && exit 1
diff --git a/.github/actions/check-file-format/check-file-format.sh b/.github/actions/check-file-format/check-file-format.sh
index 9581df0d..cc4b3d39 100755
--- a/.github/actions/check-file-format/check-file-format.sh
+++ b/.github/actions/check-file-format/check-file-format.sh
@@ -55,13 +55,13 @@ function main() {
       filter="git ls-files -z"
       ;;
     "staged-changes")
-      filter="git diff --diff-filter=ACMRT --name-only --cached -z"
+      filter="git diff --diff-filter=ACMRT --name-only --cached --ignore-submodules=all -z"
       ;;
     "working-tree-changes")
-      filter="git diff --diff-filter=ACMRT --name-only -z"
+      filter="git diff --diff-filter=ACMRT --name-only --ignore-submodules=all -z"
       ;;
     "branch")
-      filter="git diff --diff-filter=ACMRT --name-only -z ${BRANCH_NAME:-origin/main}"
+      filter="git diff --diff-filter=ACMRT --name-only --ignore-submodules=all -z ${BRANCH_NAME:-origin/main}"
       ;;
     *)
       echo "Unrecognised check mode: $check" >&2 && exit 1
diff --git a/.github/actions/check-markdown-format/check-markdown-format.sh b/.github/actions/check-markdown-format/check-markdown-format.sh
index 8bc29ab9..f24d1d65 100755
--- a/.github/actions/check-markdown-format/check-markdown-format.sh
+++ b/.github/actions/check-markdown-format/check-markdown-format.sh
@@ -42,13 +42,13 @@ function main() {
       files="$(git ls-files "*.md")"
       ;;
     "staged-changes")
-      files="$(git diff --diff-filter=ACMRT --name-only --cached "*.md")"
+      files="$(git diff --diff-filter=ACMRT --name-only --cached --ignore-submodules=all "*.md")"
       ;;
     "working-tree-changes")
-      files="$(git diff --diff-filter=ACMRT --name-only "*.md")"
+      files="$(git diff --diff-filter=ACMRT --name-only --ignore-submodules=all "*.md")"
       ;;
     "branch")
-      files="$( (git diff --diff-filter=ACMRT --name-only "${BRANCH_NAME:-origin/main}" "*.md"; git diff --name-only "*.md") | sort | uniq )"
+      files="$( (git diff --diff-filter=ACMRT --name-only --ignore-submodules=all "${BRANCH_NAME:-origin/main}" "*.md"; git diff --name-only --ignore-submodules=all "*.md") | sort | uniq )"
       ;;
   esac
 
diff --git a/.github/actions/check-todo-usage/check-todos.sh b/.github/actions/check-todo-usage/check-todos.sh
index bf9ef386..a2edeace 100755
--- a/.github/actions/check-todo-usage/check-todos.sh
+++ b/.github/actions/check-todo-usage/check-todos.sh
@@ -65,13 +65,13 @@ function get_files_to_check() {
   local mode="$1"
   case "$mode" in
     staged-changes)
-      git diff --diff-filter=ACMRT --name-only --cached # ACMRT only show files added, copied, modified, renamed or that had their type changed (eg. file → symlink) in this commit. This leaves out deleted files.
+      git diff --diff-filter=ACMRT --name-only --cached --ignore-submodules=all # ACMRT only show files added, copied, modified, renamed or that had their type changed (eg. file → symlink) in this commit. This leaves out deleted files.
       ;;
     working-tree-changes)
-      git ls-files --others --exclude-standard && git diff --diff-filter=ACMRT --name-only
+      git ls-files --others --exclude-standard && git diff --diff-filter=ACMRT --name-only --ignore-submodules=all
       ;;
     branch)
-      git diff --diff-filter=ACMRT --name-only ${BRANCH_NAME:-origin/main}
+      git diff --diff-filter=ACMRT --name-only --ignore-submodules=all ${BRANCH_NAME:-origin/main}
       ;;
     all)
       git ls-files && git ls-files --others --exclude-standard