diff --git a/roles/custom/matrix-synapse/vars/main.yml b/roles/custom/matrix-synapse/vars/main.yml
index a275c815e..0b21a60d0 100644
--- a/roles/custom/matrix-synapse/vars/main.yml
+++ b/roles/custom/matrix-synapse/vars/main.yml
@@ -80,14 +80,17 @@ matrix_synapse_workers_federation_reader_federation_endpoints:
 # - some of these paths are auth-sensitive or deployment-sensitive, so we intentionally keep them out of the broad worker route model unless explicitly handled elsewhere
 #
 # Basically, we aim to cover most spec client APIs here. Skipping `/_synapse/client` is intentional and conservative.
-matrix_synapse_workers_generic_worker_client_server_endpoints: "{{ matrix_synapse_workers_generic_worker_endpoints | default([]) | map('regex_search', '.*/_matrix/client.*') | list | difference([none]) }}"
+# Here and in `matrix_synapse_workers_generic_worker_federation_endpoints` below, `reject('none')` is used instead of `difference([none])`.
+# `difference` returns the items in an order that changes between Ansible runs, which would rewrite the reverse-proxy companion configuration
+# (and restart its service) on every run.
+matrix_synapse_workers_generic_worker_client_server_endpoints: "{{ matrix_synapse_workers_generic_worker_endpoints | default([]) | map('regex_search', '.*/_matrix/client.*') | reject('none') | list }}"
 
 # A Synapse generic worker can handle both federation and client-server API endpoints.
 # We wish to split these, as we normally serve federation separately and don't want them mixed up.
 #
 # This is some ugly Ansible/Jinja2 hack (seen here: https://stackoverflow.com/a/47831492),
 # which takes a list of various strings and removes the ones NOT containing `/_matrix/federation` or `/_matrix/key` anywhere in them.
-matrix_synapse_workers_generic_worker_federation_endpoints: "{{ matrix_synapse_workers_generic_worker_endpoints | default([]) | map('regex_search', matrix_synapse_workers_generic_worker_federation_endpoints_regex) | list | difference([none]) }}"
+matrix_synapse_workers_generic_worker_federation_endpoints: "{{ matrix_synapse_workers_generic_worker_endpoints | default([]) | map('regex_search', matrix_synapse_workers_generic_worker_federation_endpoints_regex) | reject('none') | list }}"
 
 # matrix_synapse_workers_generic_worker_federation_endpoints_regex contains the regex used in matrix_synapse_workers_generic_worker_federation_endpoints.
 # It's intentionally put in a separate variable, to avoid tripping ansible-lint's jinja[spacing] rule.