diff --git a/test/completion/pep0484_generic_parameters.py b/test/completion/pep0484_generic_parameters.py
index dca64299..efc7c926 100644
--- a/test/completion/pep0484_generic_parameters.py
+++ b/test/completion/pep0484_generic_parameters.py
@@ -223,6 +223,21 @@ first(specialised_instance)
 values(specialised_instance)[0]
 
 
+# Test that classes which have gneeric ancestry but neither they nor their
+# parents are not generic are still inferred correctly.
+class ChildOfSpecialised(Specialised):
+    pass
+
+
+child_of_specialised_instance = NotImplemented  # type: ChildOfSpecialised
+
+#? int()
+first(child_of_specialised_instance)
+
+#? str()
+values(child_of_specialised_instance)[0]
+
+
 # Test that unbound generics are inferred as much as possible
 class CustomPartialGeneric1(Mapping[str, T]):
     pass