diff --git a/pyproject.toml b/pyproject.toml
index 7cd0331..55fcbcb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,6 +21,9 @@ dependencies = [
     "pyxdg",
     "PyGObject >= 3.14.0, <= 3.51.0",
     "pyserial>=3.5",
+    "sphinx>=9.0.4",
+    "sphinxcontrib-bibtex>=2.7.0",
+    "sphinx-rtd-theme>=3.1.0",
 ]
 authors = [
   {name = "Achim Gädke"},