diff --git a/mypy/messages.py b/mypy/messages.py
index dadce149680e8..6567d9d96d0bb 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -2942,9 +2942,9 @@ def [T <: int] f(self, x: int, y: T) -> None
         for tvar in tp.variables:
             if isinstance(tvar, TypeVarType):
                 upper_bound = get_proper_type(tvar.upper_bound)
-                if (
+                if not (
                     isinstance(upper_bound, Instance)
-                    and upper_bound.type.fullname != "builtins.object"
+                    and upper_bound.type.fullname == "builtins.object"
                 ):
                     tvars.append(f"{tvar.name}: {format_type_bare(upper_bound, options)}")
                 elif tvar.values:
diff --git a/test-data/unit/check-functions.test b/test-data/unit/check-functions.test
index b681c544a6bda..96f9815019e63 100644
--- a/test-data/unit/check-functions.test
+++ b/test-data/unit/check-functions.test
@@ -1428,6 +1428,20 @@ else:
                                     # N: Redefinition: \
                                     # N:     def f(x: int = ...) -> None
 
+[case testIncompatibleConditionalFunctionDefinition4]
+from typing import Any, Union, TypeVar
+T1 = TypeVar('T1')
+T2 = TypeVar('T2', bound=Union[int, str])
+x = None # type: Any
+if x:
+    def f(x: T1) -> T1: pass
+else:
+    def f(x: T2) -> T2: pass # E: All conditional function variants must have identical signatures \
+                             # N: Original: \
+                             # N:     def [T1] f(x: T1) -> T1 \
+                             # N: Redefinition: \
+                             # N:     def [T2: Union[int, str]] f(x: T2) -> T2
+
 [case testConditionalFunctionDefinitionUsingDecorator1]
 from typing import Callable