diff --git a/Lib/cmd.py b/Lib/cmd.py
index 51495fb32160b0..ee124005e1c51b 100644
--- a/Lib/cmd.py
+++ b/Lib/cmd.py
@@ -111,7 +111,7 @@ def cmdloop(self, intro=None):
                 import readline
                 self.old_completer = readline.get_completer()
                 readline.set_completer(self.complete)
-                if readline.backend == "editline":
+                if getattr(readline, 'backend', None) == "editline":
                     if self.completekey == 'tab':
                         # libedit uses "^I" instead of "tab"
                         command_string = "bind ^I rl_complete"
diff --git a/Lib/pdb.py b/Lib/pdb.py
index eee0273fdc463f..0464b288ef825a 100644
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -364,7 +364,7 @@ def __init__(self, completekey='tab', stdin=None, stdout=None, skip=None,
         bdb.Bdb.__init__(self, skip=skip, backend=backend if backend else get_default_backend())
         cmd.Cmd.__init__(self, completekey, stdin, stdout)
         sys.audit("pdb.Pdb")
-        if stdin:
+        if stdin is not None and stdin is not sys.stdin:
             self.use_rawinput = False
         self.prompt = '(Pdb) '
         self.aliases = {}
diff --git a/Misc/NEWS.d/next/Windows/2025-12-25-00-38-20.gh-issue-143082.CYUeux.rst b/Misc/NEWS.d/next/Windows/2025-12-25-00-38-20.gh-issue-143082.CYUeux.rst
new file mode 100644
index 00000000000000..0652c4ca930027
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2025-12-25-00-38-20.gh-issue-143082.CYUeux.rst
@@ -0,0 +1 @@
+Fix :mod:`pdb` arrow key history not working when ``stdin`` is ``sys.stdin``.