diff --git a/Lib/test/test_readline.py b/Lib/test/test_readline.py
index b9d082b3597f13..6f793939fe298a 100644
--- a/Lib/test/test_readline.py
+++ b/Lib/test/test_readline.py
@@ -405,6 +405,11 @@ def test_write_read_limited_history(self):
         # So, we've only tested that the read did not fail.
         # See TestHistoryManipulation for the full test.
 
+    def test_environment_is_not_modified(self):
+        original_env = dict(os.environ)
+        os.reload_environ()
+        self.assertEqual(dict(os.environ), original_env)
+
 
 @unittest.skipUnless(support.Py_GIL_DISABLED, 'these tests can only possibly fail with GIL disabled')
 class FreeThreadingTest(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-05-07-18-31-31.gh-issue-46927.sF02gj.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-07-18-31-31.gh-issue-46927.sF02gj.rst
new file mode 100644
index 00000000000000..3ba9757c8acb5d
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-05-07-18-31-31.gh-issue-46927.sF02gj.rst
@@ -0,0 +1,2 @@
+Prevent :mod:`readline` from overriding the ``COLUMNS`` and ``LINES``
+environment variables, as values are not updated on terminal resize.
diff --git a/Modules/readline.c b/Modules/readline.c
index 0dd99dc66c08e9..f60bdd33b00e2d 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -1323,6 +1323,13 @@ setup_readline(readlinestate *mod_state)
     /* The name must be defined before initialization */
     rl_readline_name = "python";
 
+#if !defined(__APPLE__)
+    /* Prevent readline from changing environment variables such as LINES and
+     * COLUMNS.
+     */
+    rl_change_environment = 0;
+#endif
+
     /* the libedit readline emulation resets key bindings etc
      * when calling rl_initialize.  So call it upfront
      */