diff --git a/docs/configuring-playbook-matrix-registration.md b/docs/configuring-playbook-matrix-registration.md
index b0240d3f..2b4b07ff 100644
--- a/docs/configuring-playbook-matrix-registration.md
+++ b/docs/configuring-playbook-matrix-registration.md
@@ -2,6 +2,8 @@
 
 The playbook can install and configure [matrix-registration](https://github.com/ZerataX/matrix-registration) for you.
 
+**WARNING**: this is a poorly maintained and buggy project. It's better to avoid using it.
+
 > matrix-registration is a simple python application to have a token based matrix registration.
 
 Use matrix-registration to **create unique registration links**, which people can use to register on your Matrix server. It allows you to **keep your server's registration closed (private)**, but still allow certain people (these having a special link) to register a user account.
diff --git a/roles/matrix-registration/defaults/main.yml b/roles/matrix-registration/defaults/main.yml
index d924551a..a5db3022 100644
--- a/roles/matrix-registration/defaults/main.yml
+++ b/roles/matrix-registration/defaults/main.yml
@@ -7,6 +7,10 @@ matrix_registration_enabled: true
 matrix_registration_container_image_self_build: false
 matrix_registration_container_image_self_build_repo: "https://github.com/ZerataX/matrix-registration"
 matrix_registration_container_image_self_build_branch: "{{ 'master' if matrix_registration_version == 'latest' else matrix_registration_version }}"
+# Controls whether we'll be patching the dependencies in `setup.py` when self-building.
+# Without patching, building will likely fail, because of the poor unbounded way dependencies are defined (e.g. `flask-limiter>=1.1.0`).
+# This is an attempt to get matrix-registration in its current (outdated) version to build.
+matrix_registration_container_image_self_build_python_dependencies_patch_enabled: true
 
 matrix_registration_base_path: "{{ matrix_base_data_path }}/matrix-registration"
 matrix_registration_config_path: "{{ matrix_registration_base_path }}/config"
diff --git a/roles/matrix-registration/tasks/setup_install.yml b/roles/matrix-registration/tasks/setup_install.yml
index 6ff2de30..36cd0fd4 100644
--- a/roles/matrix-registration/tasks/setup_install.yml
+++ b/roles/matrix-registration/tasks/setup_install.yml
@@ -68,6 +68,14 @@
   register: matrix_registration_git_pull_results
   when: "matrix_registration_container_image_self_build|bool"
 
+# See: https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/1864
+- name: Patch setup.py to allow self-built version to work
+  lineinfile:
+    path: "{{ matrix_registration_docker_src_files_path }}/setup.py"
+    regexp: 'flask-limiter'
+    line: '"flask-limiter~=1.1.0", "Markupsafe<2.1",'
+  when: "matrix_registration_container_image_self_build|bool and matrix_registration_container_image_self_build_python_dependencies_patch_enabled|bool"
+
 - name: Ensure matrix-registration Docker image is built
   docker_image:
     name: "{{ matrix_registration_docker_image }}"