diff --git a/mypy/checker.py b/mypy/checker.py
index 332b73825394..56690e9db40f 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -56,7 +56,6 @@
     make_inferred_type_note,
     pretty_seq,
 )
-from mypy.mixedtraverser import MixedTraverserVisitor
 from mypy.mro import MroError, calculate_mro
 from mypy.nodes import (
     ARG_NAMED,