diff --git a/pyproject.toml b/pyproject.toml
index 72dd83c..e1386aa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,9 +39,6 @@ classifiers = [
     "Topic :: Text Processing",
     "Topic :: Utilities",
 ]
-dependencies = [
-    "Sphinx>=5",
-]
 dynamic = ["version"]
 
 [project.optional-dependencies]
@@ -72,3 +69,8 @@ include = [
 
 [tool.mypy]
 ignore_missing_imports = true
+
+[project.optional-dependencies]
+standalone = [
+  "sphinx > 5",
+]
\ No newline at end of file