diff --git a/README.md b/README.md
index 5fe9678..7008b9d 100644
--- a/README.md
+++ b/README.md
@@ -60,6 +60,10 @@ legacy Python 3.6 web stack: malformed `From`/`Subject` headers, nested
 gettext catalogs. It also normalizes non-ASCII sender addresses and backports
 the byte-oriented delivery used by newer `mailman-hyperkitty` releases, so
 surrogate-escaped message bytes do not pass through Requests as Unicode text.
+Named MIME parts whose content type is missing or empty are extracted as binary
+attachments instead of being appended to the plain-text message body. As an
+additional safeguard, the NUL filtering introduced by django-mailman3 1.3.6 is
+backported for scrubbed text fields only; binary attachments remain unchanged.
 Enable it only for the known package versions:
 
 ```yaml
diff --git a/templates/mailman-legacy-hyperkitty-compatibility.py.j2 b/templates/mailman-legacy-hyperkitty-compatibility.py.j2
index a355932..de351ca 100644
--- a/templates/mailman-legacy-hyperkitty-compatibility.py.j2
+++ b/templates/mailman-legacy-hyperkitty-compatibility.py.j2
@@ -113,6 +113,42 @@ SCRUB_NEW = '''        if ctype == 'message/rfc822':
                 decodedpayload = str(payload)
 '''
 
+SCRUB_NAMED_TEXT_ATTACHMENT_OLD = '''            if ctype == 'text/plain':
+                if part.is_attachment():
+                    attachments.append(self._parse_attachment(part, part_num))
+                    part.set_content('\\n')
+'''
+SCRUB_NAMED_TEXT_ATTACHMENT_NEW = '''            if ctype == 'text/plain':
+                filename = part.get_filename()
+                if part.is_attachment() or filename:
+                    # A missing or empty MIME type defaults to text/plain. If
+                    # a filename is present, keep binary data out of the body.
+                    raw_content_type = part.get('Content-Type', '')
+                    declared_type = str(raw_content_type).split(';', 1)[0].strip()
+                    if filename and not declared_type:
+                        part.set_type('application/octet-stream')
+                    attachments.append(self._parse_attachment(part, part_num))
+                    part.set_content('\\n')
+'''
+
+SCRUB_NUL_ONE_PART_OLD = '''        if next_part_match:
+            result = result[0:next_part_match.start(0)]
+        return result
+'''
+SCRUB_NUL_ONE_PART_NEW = '''        if next_part_match:
+            result = result[0:next_part_match.start(0)]
+        # Backport from django-mailman3 1.3.6: PostgreSQL text fields cannot
+        # contain NUL characters.
+        return re.sub('\\x00', '', result)
+'''
+
+SCRUB_NUL_MULTIPART_OLD = '''            return '\\n'.join(text)
+'''
+SCRUB_NUL_MULTIPART_NEW = '''            # Backport from django-mailman3 1.3.6: PostgreSQL text fields
+            # cannot contain NUL characters.
+            return re.sub('\\x00', '', '\\n'.join(text))
+'''
+
 MAILMAN_HYPERKITTY_SEND_OLD = '''            message_text = msg.as_string()
         except (MessageError, KeyError) as error:
 '''
@@ -185,13 +221,26 @@ def patch_hyperkitty(source):
 
 
 def patch_scrubber(source):
-    if SCRUB_NEW in source:
-        if SCRUB_OLD in source:
-            raise RuntimeError('django-mailman3 compatibility patch is ambiguous')
-        return source, False
-    return replace_once(
-        source, SCRUB_OLD, SCRUB_NEW,
-        'django-mailman3 message/rfc822 handling'), True
+    updated = source
+    changed = False
+    replacements = (
+        (SCRUB_OLD, SCRUB_NEW, 'django-mailman3 message/rfc822 handling'),
+        (SCRUB_NAMED_TEXT_ATTACHMENT_OLD, SCRUB_NAMED_TEXT_ATTACHMENT_NEW,
+         'django-mailman3 named text attachment handling'),
+        (SCRUB_NUL_ONE_PART_OLD, SCRUB_NUL_ONE_PART_NEW,
+         'django-mailman3 single-part NUL handling'),
+        (SCRUB_NUL_MULTIPART_OLD, SCRUB_NUL_MULTIPART_NEW,
+         'django-mailman3 multipart NUL handling'),
+    )
+    for old, new, description in replacements:
+        if new in updated:
+            if old in updated:
+                raise RuntimeError(
+                    '{} compatibility patch is ambiguous'.format(description))
+            continue
+        updated = replace_once(updated, old, new, description)
+        changed = True
+    return updated, changed
 
 
 def patch_mailman_hyperkitty(source):