diff --git a/python/ql/src/Classes/InconsistentMRO.ql b/python/ql/src/Classes/InconsistentMRO.ql
index aa319d56114e..93dde9288ddb 100644
--- a/python/ql/src/Classes/InconsistentMRO.ql
+++ b/python/ql/src/Classes/InconsistentMRO.ql
@@ -12,19 +12,27 @@
  */
 
 import python
-private import LegacyPointsTo
+private import semmle.python.dataflow.new.internal.DataFlowDispatch
 
-ClassObject left_base(ClassObject type, ClassObject base) {
-  exists(int i | i > 0 and type.getBaseType(i) = base and result = type.getBaseType(i - 1))
+/**
+ * Gets the `i`th base class of `cls`, if it can be resolved to a user-defined class.
+ */
+Class getBaseType(Class cls, int i) {
+  cls.getBase(i) = classTracker(result).asExpr() and
+  result != cls
+}
+
+Class left_base(Class type, Class base) {
+  exists(int i | i > 0 and getBaseType(type, i) = base and result = getBaseType(type, i - 1))
 }
 
-predicate invalid_mro(ClassObject t, ClassObject left, ClassObject right) {
-  t.isNewStyle() and
+predicate invalid_mro(Class t, Class left, Class right) {
+  DuckTyping::isNewStyle(t) and
   left = left_base(t, right) and
-  left = right.getAnImproperSuperType()
+  left = getADirectSuperclass*(right)
 }
 
-from ClassObject t, ClassObject left, ClassObject right
+from Class t, Class left, Class right
 where invalid_mro(t, left, right)
 select t,
   "Construction of class " + t.getName() +
diff --git a/python/ql/test/2/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected b/python/ql/test/2/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
index ebec9bb61e0b..93d12fc0a454 100644
--- a/python/ql/test/2/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
+++ b/python/ql/test/2/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
@@ -1 +1 @@
-| inconsistent_mro.py:9:1:9:14 | class Z | Construction of class Z can fail due to invalid method resolution order(MRO) for bases $@ and $@. | inconsistent_mro.py:3:1:3:16 | class X | X | inconsistent_mro.py:6:1:6:11 | class Y | Y |
+| inconsistent_mro.py:9:1:9:14 | Class Z | Construction of class Z can fail due to invalid method resolution order(MRO) for bases $@ and $@. | inconsistent_mro.py:3:1:3:16 | Class X | X | inconsistent_mro.py:6:1:6:11 | Class Y | Y |
diff --git a/python/ql/test/3/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected b/python/ql/test/3/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
index ca0a64f70e1b..93d12fc0a454 100644
--- a/python/ql/test/3/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
+++ b/python/ql/test/3/query-tests/Classes/inconsistent-mro/InconsistentMRO.expected
@@ -1,2 +1 @@
-| inconsistent_mro.py:9:1:9:14 | class Z | Construction of class Z can fail due to invalid method resolution order(MRO) for bases $@ and $@. | inconsistent_mro.py:3:1:3:16 | class X | X | inconsistent_mro.py:6:1:6:11 | class Y | Y |
-| inconsistent_mro.py:16:1:16:19 | class N | Construction of class N can fail due to invalid method resolution order(MRO) for bases $@ and $@. | file://:Compiled Code:0:0:0:0 | builtin-class object | object | inconsistent_mro.py:12:1:12:8 | class O | O |
+| inconsistent_mro.py:9:1:9:14 | Class Z | Construction of class Z can fail due to invalid method resolution order(MRO) for bases $@ and $@. | inconsistent_mro.py:3:1:3:16 | Class X | X | inconsistent_mro.py:6:1:6:11 | Class Y | Y |