diff --git a/src/libstore/dummy-store.cc b/src/libstore/dummy-store.cc
index 509b7a0b1..6c8cb3480 100644
--- a/src/libstore/dummy-store.cc
+++ b/src/libstore/dummy-store.cc
@@ -148,7 +148,7 @@ struct DummyStoreImpl : DummyStore
     /**
      * The dummy store is incapable of *not* trusting! :)
      */
-    virtual std::optional<TrustedFlag> isTrustedClient() override
+    std::optional<TrustedFlag> isTrustedClient() override
     {
         return Trusted;
     }