diff --git a/stdlib/2and3/logging/__init__.pyi b/stdlib/2and3/logging/__init__.pyi
index 79ee6261b..131179471 100644
--- a/stdlib/2and3/logging/__init__.pyi
+++ b/stdlib/2and3/logging/__init__.pyi
@@ -186,7 +186,7 @@ class Formatter:
                      datefmt: Optional[str] = ...) -> None: ...
 
     def format(self, record: LogRecord) -> str: ...
-    def formatTime(self, record: LogRecord, datefmt: str = ...) -> str: ...
+    def formatTime(self, record: LogRecord, datefmt: Optional[str] = ...) -> str: ...
     def formatException(self, exc_info: _SysExcInfoType) -> str: ...
     if sys.version_info >= (3,):
         def formatMessage(self, record: LogRecord) -> str: ...  # undocumented