diff --git a/tools/pr_affecting_file.sh b/tools/pr_affecting_file.sh
new file mode 100644
index 0000000..f3680d2
--- /dev/null
+++ b/tools/pr_affecting_file.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+curl -s https://api.github.com/repos/lnbook/lnbook/pulls | jq '.[]|.number' | while read pr; do
+  git fetch --quiet github refs/pull/$pr/head
+  if git show --pretty=format:'' --name-only FETCH_HEAD | grep -q $1; then
+    echo "PR $pr"
+  fi
+done