diff --git a/mypy/subtypes.py b/mypy/subtypes.py
index af35821d7ef4..087e10a04e6f 100644
--- a/mypy/subtypes.py
+++ b/mypy/subtypes.py
@@ -290,9 +290,12 @@ def visit_instance(self, left: Instance) -> bool:
                     if isinstance(tvar, TypeVarType):
                         if not self.check_type_parameter(lefta, righta, tvar.variance):
                             nominal = False
-                    else:
+                    elif isinstance(tvar, ParamSpecType):
                         if not self.check_type_parameter(lefta, righta, COVARIANT):
                             nominal = False
+                    else:
+                        if not is_equivalent(lefta, righta):
+                            nominal = False
                 if nominal:
                     TypeState.record_subtype_cache_entry(self._subtype_kind, left, right)
                 return nominal