diff --git a/.github/update-wide-integer b/.github/update-wide-integer
new file mode 100755
index 000000000..bd966e317
--- /dev/null
+++ b/.github/update-wide-integer
@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+SOURCE_FILE_PATH=$(
+  cd "$(dirname "$0")"/..
+  pwd
+)/include/cnl/_impl/ckormanyos/uintwide_t.h
+
+git clone https://github.com/ckormanyos/wide-integer/
+
+echo "// NOLINTBEGIN(*)" > "${SOURCE_FILE_PATH}"
+echo "// copied from https://github.com/ckormanyos/wide-integer/" >> "${SOURCE_FILE_PATH}"
+echo "" >> "${SOURCE_FILE_PATH}"
+
+cat wide-integer/math/wide_integer/uintwide_t.h >> "${SOURCE_FILE_PATH}"
+
+echo "// NOLINTEND(*)" >> "${SOURCE_FILE_PATH}"
diff --git a/.github/workflows/wide-integer.yml b/.github/workflows/wide-integer.yml
new file mode 100644
index 000000000..a3f991eaf
--- /dev/null
+++ b/.github/workflows/wide-integer.yml
@@ -0,0 +1,27 @@
+---
+name: pr
+
+on:
+  pull_request:
+    branches:
+      - '**'
+  push:
+    branches:
+      - main
+
+jobs:
+  # Check for updates to wide-integer library
+  wide-integer:
+    runs-on: ubuntu-18.04
+    container: johnmcfarlane/cnl_ci:base-21.10
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Extract wide-integer source
+        shell: bash
+        run: $GITHUB_WORKSPACE/.github/update-wide-integer
+
+      - name: Check for changes
+        shell: bash
+        run: git diff --exit-code
+...