diff --git a/pyproject.toml b/pyproject.toml
index 8f6d718..79b1716 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,7 +46,7 @@ dev = [
 doc = [
   "m2r2==0.3.2",
   "sphinxcontrib-apidoc==0.3.0",
-  "sphinx_rtd_theme==1.2.2",
+  "sphinx_rtd_theme==3.0.1",
 ]
 test = [
   "pytest-cov==4.1.0",