diff --git a/lib/selectors/socket-selectors.js b/lib/selectors/socket-selectors.js
--- a/lib/selectors/socket-selectors.js
+++ b/lib/selectors/socket-selectors.js
@@ -166,6 +166,7 @@
           const { failUnmentioned } = serverRequest;
           for (const spec of values(specPerInnerHashKey)) {
             const innerHashKey = spec.innerHashSpec?.hashKey;
+            // $FlowFixMe
             if (!failUnmentioned?.[spec.hashKey] || !innerHashKey) {
               continue;
             }