diff --git a/scripts/toggle-workspace.sh b/scripts/toggle-workspace.sh
new file mode 100755
index 000000000..7ad7aeed3
--- /dev/null
+++ b/scripts/toggle-workspace.sh
@@ -0,0 +1,132 @@
+#!/usr/bin/env bash
+#
+# Updates .bazelrc files to enable or disable WORKSPACE builds.
+#
+# This is for testing `WORKSPACE` and Bzlmod compatibility. The produced changes
+# should never be checked in. Run this script with the `restore` argument to
+# revert them before committing.
+
+ROOTDIR="${BASH_SOURCE[0]%/*}/.."
+cd "$ROOTDIR"
+
+if [[ "$?" -ne 0 ]]; then
+  echo "Could not change to $ROOTDIR." >&2
+  exit 1
+fi
+
+usage() {
+  local lines=()
+  while IFS='' read line; do
+    if [[ "${line:0:1}" != '#' ]]; then
+      printf '%s\n' "Usage: $0 [ on | off | restore ]" "${lines[@]:1}" >&2
+      exit "$1"
+    fi
+    lines+=("${line:2}")
+  done <$0
+}
+
+update_bazelrc_files() {
+  local mode="$1"
+  local workspace_options="build --noenable_bzlmod"
+  local bzlmod_options="build --enable_bzlmod"
+  local bazel_version="$(bazel --version 2>&1)"
+
+  if [[ "$?" -ne 0 ]]; then
+    echo "failed to run `bazel --version`: $bazel_version" >&2
+    exit 1
+  elif [[ "${bazel_version#* }" =~ ^(7|8)\. ]]; then
+    workspace_options="${workspace_options} --enable_workspace"
+    bzlmod_options="${bzlmod_options} --noenable_workspace"
+  fi
+
+  local enabled_options="$workspace_options"
+  local disabled_options="$bzlmod_options"
+
+  if [[ "$mode" == "off" ]]; then
+    enabled_options="$bzlmod_options"
+    disabled_options="$workspace_options"
+  fi
+
+  already_enabled="($enabled_options|import [./]*/.bazelrc)"
+
+  # Searches for WORKSPACE instead of .bazelrc because not all repos may have a
+  # .bazelrc file.
+  while IFS='' read repo_marker_path; do
+    local repo_path="${repo_marker_path%/*}"
+    local bazelrc_path="$repo_path/.bazelrc"
+
+    # The top level repo is a special case.
+    if [[ "$repo_path" == "$repo_marker_path" ]]; then
+      bazelrc_path="./.bazelrc"
+    fi
+
+    if [[ ! -f "$bazelrc_path" ]]; then
+      echo "$enabled_options" > "$bazelrc_path"
+      continue
+    fi
+
+    content="$(< "$bazelrc_path")"
+
+    if [[ "$content" =~ $disabled_options ]]; then
+      echo "${content//$disabled_options/$enabled_options}" >"$bazelrc_path"
+    elif [[ ! "$content" =~ $already_enabled ]]; then
+      echo "$enabled_options" >> "$bazelrc_path"
+    fi
+
+  done < <(find [A-Za-z0-9]* -name "WORKSPACE")
+}
+
+restore_bazelrc_files() {
+  local staged=()
+  local unstaged=()
+  local untracked=()
+
+  get_bazelrc_files_by_status
+
+  if [[ "${#staged[@]}" -ne 0 ]]; then
+    # Staged files can be untracked after unstaging, so recalculate.
+    git restore --staged "${staged[@]}"
+    unstaged=()
+    untracked=()
+    get_bazelrc_files_by_status
+  fi
+
+  if [[ "${#unstaged[@]}" -ne 0 ]]; then
+    git restore "${unstaged[@]}"
+  fi
+
+  if [[ "${#untracked[@]}" -ne 0 ]]; then
+    git clean -f "${untracked[@]}"
+  fi
+}
+
+get_bazelrc_files_by_status() {
+  while IFS='' read status_line; do
+    local status_code="${status_line:0:1}"
+    local bazelrc_file="${status_line:3}"
+
+    if [[ "$status_code" == '?' ]]; then
+      untracked+=("$bazelrc_file")
+    elif [[ "$status_code" == ' ' ]]; then
+      unstaged+=("$bazelrc_file")
+    else
+      staged+=("$bazelrc_file")
+    fi
+  done < <(git status -s '.bazelrc' '**/.bazelrc')
+}
+
+if [[ "$#" -ne 1 ]]; then
+  usage 1
+fi
+
+case "$1" in
+  on|off)
+    update_bazelrc_files "$1"
+    ;;
+  restore)
+    restore_bazelrc_files
+    ;;
+  *)
+    usage 1
+    ;;
+esac