diff --git a/scripts/usage-run.py b/scripts/usage-run.py
index b75969c..c71f5bb 100644
--- a/scripts/usage-run.py
+++ b/scripts/usage-run.py
@@ -54,7 +54,11 @@ def turn(text):
         q = urllib.parse.parse_qs(urllib.parse.urlparse(loc).query)
         return {
             "reply": q.get("r", [""])[0],
-            "source": q.get("src", q.get("source", [""]))[0],
+            # "s", not "src". cmd/mavweb/chat.go writes the badge under that
+            # name, and reading the wrong one cost both fortnight runs their
+            # source column: every finding in those docs is inferred from the
+            # reply wording instead.
+            "source": q.get("s", [""])[0],
             "trace": q.get("t", [""])[0],
             "secs": dt,
         }