diff --git a/tests/harness/corpus-costs/8115-error-prototype-identity.js.json b/tests/harness/corpus-costs/8115-error-prototype-identity.js.json
new file mode 100644
index 000000000..57bb2b280
--- /dev/null
+++ b/tests/harness/corpus-costs/8115-error-prototype-identity.js.json
@@ -0,0 +1 @@
+{ "plain": 5600, "san": 5100 }