diff --git a/java/ql/test/library-tests/functional-interfaces/Test.java b/java/ql/test/library-tests/functional-interfaces/Test.java
index ad0d4c079b42..a07881e07be6 100644
--- a/java/ql/test/library-tests/functional-interfaces/Test.java
+++ b/java/ql/test/library-tests/functional-interfaces/Test.java
@@ -21,9 +21,19 @@ interface NotFunctional {
   interface FunctionalWithObjectMethods {
     int f();
 
+    // Not actually abstract; implementation comes from Object
+    boolean equals(Object obj);
+    int hashCode();
     String toString();
+  }
 
-    int hashCode();
+  interface NotFunctionalWithObjectMethods {
+    int f();
+
+    // Increases their visibility from `protected` to `public`; this requires subclasses to implement them
+    // See also JLS section "Functional Interfaces" which explicitly covers this
+    Object clone();
+    void finalize();
   }
 
 }