diff --git a/changelog.d/20422.bugfix b/changelog.d/20422.bugfix
new file mode 100644
index 0000000000..4a6e587c97
--- /dev/null
+++ b/changelog.d/20422.bugfix
@@ -0,0 +1,4 @@
+Fix clearing user status for clients that send a `null` profile field value.
+
+When `include_profile_updates_in_sync` is enabled, Synapse will continue to accept `null` custom profile field values
+until clients have had a sufficient time to change their behaviour. This special casing is tracked in [this issue](https://github.com/element-hq/synapse/issues/20424).
\ No newline at end of file
diff --git a/synapse/rest/client/profile.py b/synapse/rest/client/profile.py
index cb527a1bb5..9c969fd235 100644
--- a/synapse/rest/client/profile.py
+++ b/synapse/rest/client/profile.py
@@ -138,6 +138,9 @@ class ProfileFieldRestServlet(RestServlet):
                     r"^/_matrix/client/unstable/uk\.tcpip\.msc4133/profile/(?P<user_id>[^/]*)/(?P<field_name>[^/]*)$"
                 )
             )
+        self._include_profile_updates_in_sync = (
+            hs.config.server.include_profile_updates_in_sync
+        )
 
     async def on_GET(
         self, request: SynapseRequest, user_id: str, field_name: str
@@ -232,13 +235,20 @@ class ProfileFieldRestServlet(RestServlet):
                 errcode=Codes.MISSING_PARAM,
             )
 
-        if new_value is None:
+        if new_value is None and not self._include_profile_updates_in_sync:
             # > Servers MAY reject null values.
             # — https://spec.matrix.org/v1.19/client-server-api/#put_matrixclientv3profileuseridkeyname
             #
             # Although we can safely handle nulls internally, for interoperability reasons it is preferable if we
             # reject them.
             # That way, clients don't accidentally rely on being able to send them.
+            #
+            # The exception is if we have the profile update stream enabled, ie send
+            # down profile updates via sync streams, we will still accept null values
+            # for some time, as Element Web depends on removing User Status via
+            # a PUT and `null` value.
+            # https://github.com/element-hq/synapse/issues/20424 tracks removing
+            # this special case once enough clients have updated.
             raise SynapseError(
                 HTTPStatus.BAD_REQUEST,
                 f"'{field_name}' cannot be `null`.",
diff --git a/tests/rest/client/test_profile.py b/tests/rest/client/test_profile.py
index 7fb03fdb3f..5bb569e08f 100644
--- a/tests/rest/client/test_profile.py
+++ b/tests/rest/client/test_profile.py
@@ -40,6 +40,7 @@ from synapse.types import UserID
 from synapse.util.clock import Clock
 
 from tests import unittest
+from tests.unittest import override_config
 from tests.utils import USE_POSTGRES_FOR_TESTS
 
 
@@ -722,6 +723,24 @@ class ProfileTestCase(unittest.HomeserverTestCase):
         self.assertEqual(channel.code, HTTPStatus.BAD_REQUEST, channel.result)
         self.assertEqual(channel.json_body["errcode"], Codes.INVALID_PARAM)
 
+    @override_config({"include_profile_updates_in_sync": True})
+    def test_null_field_is_not_rejected_if_profile_update_stream_enabled(self) -> None:
+        """
+        Tests that setting a field to `null` is not rejected if profile update
+        stream is configured active.
+
+        See https://github.com/element-hq/synapse/issues/20424 for removing
+        this special case.
+        """
+        channel = self.make_request(
+            "PUT",
+            f"/_matrix/client/v3/profile/{self.owner}/org.example.custom_field",
+            content={"org.example.custom_field": None},
+            access_token=self.owner_tok,
+        )
+        self.assertEqual(channel.code, HTTPStatus.OK, channel.result)
+        self.assertFalse("errcode" in channel.json_body.keys())
+
     def test_set_custom_field_noauth(self) -> None:
         channel = self.make_request(
             "PUT",