diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 2a9f677..eb89090 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -32,6 +32,7 @@ sphinx:
 # See https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
 python:
   install:
-    - requirements: docs/requirements.txt
     - method: pip
       path: .
+      extra_requirements:
+        - docs
diff --git a/docs/requirements.txt b/docs/requirements.txt
deleted file mode 100644
index de280c0..0000000
--- a/docs/requirements.txt
+++ /dev/null
@@ -1,16 +0,0 @@
-# For the package
-ase>=3.22.1
-plotly>=5.19.0
-tqdm>=4.66.2
-pandas>=2.2.0
-scipy>=1.12.0
-lightning>=2.2.1
-jsonargparse[signatures]>=4.27.7
-numpy<=1.26.4  # Avoid dependency conflicts.
-# For the documentation
-sphinx==7.3.7
-kaleido==0.2.1
-sphinx-rtd-theme==3.0.2
-sphinx-copybutton==0.5.2
-sphinx-design==0.6.0
-sphinx-gallery==0.16.0
diff --git a/pyproject.toml b/pyproject.toml
index 4372919..a30ef58 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,3 +48,13 @@ Documentation = "https://aidsorb.readthedocs.io/en/stable/"
 [project.scripts]
 aidsorb = "aidsorb._cli:aidsorb_cli"
 aidsorb-lit = "aidsorb._cli:lightning_cli"
+
+[project.optional-dependencies]
+docs = [
+    "sphinx==7.3.7",
+    "sphinx-rtd-theme==3.0.2",
+    "sphinx-copybutton==0.5.2",
+    "sphinx-design==0.6.0",
+    "sphinx-gallery==0.16.0",
+    "kaleido==0.2.1",
+]