diff --git a/.github/mistaken-pull-closer.yml b/.github/mistaken-pull-closer.yml
new file mode 100644
index 0000000000..cbab2c436a
--- /dev/null
+++ b/.github/mistaken-pull-closer.yml
@@ -0,0 +1,13 @@
+# `true` will close all PRs.
+filters:
+  - true
+
+# The message to post to the closed PR.
+commentBody: |
+  Thanks for your contribution!  Unfortunately, we don't use GitHub pull
+  requests to manage code contributions to this repository.  Instead, please
+  see the [contributing guide](https://google.github.io/crosvm/contributing.html)
+  which provides full instructions on how to get involved.
+
+# Whether to add a label to the closed PR.
+addLabel: false