diff --git a/src/sql/upgrade-33.sql b/src/sql/upgrade-33.sql
new file mode 100644
index 00000000..62f4a49f
--- /dev/null
+++ b/src/sql/upgrade-33.sql
@@ -0,0 +1,7 @@
+create table FailedPaths (
+    path text primary key not null
+);
+
+create rule IdempotentInsert as on insert to FailedPaths
+  where exists (select 1 from FailedPaths where path = new.path)
+  do instead nothing;