diff --git a/README.md b/README.md
index 4cd4aeb..14217b8 100644
--- a/README.md
+++ b/README.md
@@ -518,6 +518,16 @@ A secure API key can be generated by any password generator.
 
     Optionally, the `force` query parameter can be passed with a value of `true` in order to make
     pict-rs spawn another task if the current one seems stuck.
+- `POST /internal/prune_missing?force={force}` Spawn a background task that will check every hash in
+    the database for an associated media file, deleting any record that is missing its media.
+
+    WARNING: This operation is very destructive. Please take backups before invoking it.
+
+    This endpoint can be hit repeatedly to check the progress of the preparations. The returned
+    `progress` value represents how many records have been marked for pruning.
+
+    Optionally, the `force` query parameter can be passed with a value of `true` in order to make
+    pict-rs spawn another task if the current one seems stuck.
 
 
 Additionally, all endpoints support setting deadlines, after which the request will cease