diff --git a/python/ql/src/Classes/ShouldBeContextManager.ql b/python/ql/src/Classes/ShouldBeContextManager.ql
index e6bf946b65a..fa7cebf9c77 100644
--- a/python/ql/src/Classes/ShouldBeContextManager.ql
+++ b/python/ql/src/Classes/ShouldBeContextManager.ql
@@ -14,8 +14,8 @@
 
 import python
 
-from ClassObject c
-where not c.isC() and not c.isContextManager() and exists(c.declaredAttribute("__del__"))
+from ClassValue c
+where not c.isBuiltin() and not c.isContextManager() and exists(c.declaredAttribute("__del__"))
 select c,
     "Class " + c.getName() +
         " implements __del__ (presumably to release some resource). Consider making it a context manager."
diff --git a/python/ql/src/analysis/RatioOfDefinitions.ql b/python/ql/src/analysis/RatioOfDefinitions.ql
index 13bad7112b9..72a3fed0e69 100644
--- a/python/ql/src/analysis/RatioOfDefinitions.ql
+++ b/python/ql/src/analysis/RatioOfDefinitions.ql
@@ -7,7 +7,7 @@ import DefinitionTracking
 
 predicate want_to_have_definition(Expr e) {
     /* not builtin object like len, tuple, etc. */
-    not exists(Object cobj | e.refersTo(cobj) and cobj.isC()) and
+    not exists(Value builtin | e.pointsTo(builtin) and builtin.isBuiltin()) and
     (
         e instanceof Name and e.(Name).getCtx() instanceof Load
         or