diff --git a/Lib/email/message.py b/Lib/email/message.py
index 41fcc2b9778798..90b135409f5c7e 100644
--- a/Lib/email/message.py
+++ b/Lib/email/message.py
@@ -862,7 +862,7 @@ def get_boundary(self, failobj=None):
         parameter, and it is unquoted.
         """
         missing = object()
-        boundary = self.get_param('boundary', missing)
+        boundary = self.get_param('boundary', missing, unquote=False)
         if boundary is missing:
             return failobj
         # RFC 2046 says that boundaries may begin but not end in w/s
diff --git a/Lib/test/test_email/test_email.py b/Lib/test/test_email/test_email.py
index b8116d073a2670..978a35abbb63ad 100644
--- a/Lib/test/test_email/test_email.py
+++ b/Lib/test/test_email/test_email.py
@@ -2209,6 +2209,42 @@ def test_boundary_with_leading_space(self):
         eq(msg.get_boundary(), '    XXXX')
         eq(len(msg.get_payload()), 2)
 
+    def test_boundary_stripped_only_once(self):
+        eq = self.assertEqual
+        msg = email.message_from_string(textwrap.dedent('''\
+            MIME-Version: 1.0
+            Content-Type: multipart/mixed; boundary="<>"
+
+            --<>
+            Content-Type: text/plain
+
+
+            --<>
+            Content-Type: text/plain
+
+            --<>--
+            '''))
+        self.assertTrue(msg.is_multipart())
+        eq(msg.get_boundary(), '<>')
+        eq(len(msg.get_payload()), 2)
+
+        msg = email.message_from_string(textwrap.dedent('''\
+            MIME-Version: 1.0
+            Content-Type: multipart/mixed; boundary=<"">
+
+            --""
+            Content-Type: text/plain
+
+
+            --""
+            Content-Type: text/plain
+
+            --""--
+            '''))
+        self.assertTrue(msg.is_multipart())
+        eq(msg.get_boundary(), '""')
+        eq(len(msg.get_payload()), 2)
+
     def test_boundary_without_trailing_newline(self):
         m = Parser().parsestr("""\
 Content-Type: multipart/mixed; boundary="===============0012394164=="
diff --git a/Misc/NEWS.d/next/Library/2025-06-24-21-08-26.gh-issue-135854.j0WMfD.rst b/Misc/NEWS.d/next/Library/2025-06-24-21-08-26.gh-issue-135854.j0WMfD.rst
new file mode 100644
index 00000000000000..95f3ced404c8b1
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-06-24-21-08-26.gh-issue-135854.j0WMfD.rst
@@ -0,0 +1 @@
+Fix :func:`email.message.Message.get_boundary` strips boundaries twice.