diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index d4503fd3..d70a3ae5 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -10,4 +10,7 @@ sphinx:
 
 python:
   install:
-    - requirements: docs/requirements.txt
+    - requirements: requirements/requirements-optionals.txt
+    - requirements: requirements/requirements-documentation.txt
+    - method: pip
+      path: .
diff --git a/docs/requirements.txt b/docs/requirements.txt
deleted file mode 100644
index 4ffe63ef..00000000
--- a/docs/requirements.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-# RTD only supports one requirements.txt file, therefore this has been created.
-# This file needs to keep in sync with tox testenv docs dependencies.
-
--r ../requirements/requirements-optionals.txt
--r ../requirements/requirements-testing.txt
--r ../requirements/requirements-documentation.txt
diff --git a/tox.ini b/tox.ini
index 236f5517..0879e756 100644
--- a/tox.ini
+++ b/tox.ini
@@ -40,6 +40,7 @@ deps =
 commands = flake8
 
 [testenv:docs]
+# keep in sync with .readthedocs.yml
 basepython = python3.8
 deps =
     -rrequirements/requirements-optionals.txt