diff --git a/poetry.lock b/poetry.lock
index 39395ef..3b03eda 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -428,7 +428,7 @@ name = "pyyaml"
 version = "5.3.1"
 description = "YAML parser and emitter for Python"
 category = "dev"
-optional = false
+optional = true
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
 
 [[package]]
@@ -535,14 +535,15 @@ test = ["pytest", "pytest-cov", "html5lib", "typed-ast", "cython"]
 
 [[package]]
 name = "sphinx-rtd-theme"
-version = "0.5.0"
+version = "1.0.0"
 description = "Read the Docs theme for Sphinx"
 category = "dev"
 optional = true
-python-versions = "*"
+python-versions = ">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*"
 
 [package.dependencies]
-sphinx = "*"
+docutils = "<0.18"
+sphinx = ">=1.6"
 
 [package.extras]
 dev = ["transifex-client", "sphinxcontrib-httpdomain", "bump2version"]
@@ -703,7 +704,7 @@ travis-ci = []
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.6"
-content-hash = "a18078e1b4a0363f1c0171e88d27f24b80e5a9e8d460836525b282702be6458f"
+content-hash = "cb45b6918284fd09ed6efecb15e04ef43f9cfc2b82ff07df1d638c2e4f4244b0"
 
 [metadata.files]
 alabaster = [
@@ -990,8 +991,8 @@ sphinx = [
     {file = "Sphinx-3.1.2.tar.gz", hash = "sha256:b9daeb9b39aa1ffefc2809b43604109825300300b987a24f45976c001ba1a8fd"},
 ]
 sphinx-rtd-theme = [
-    {file = "sphinx_rtd_theme-0.5.0-py2.py3-none-any.whl", hash = "sha256:373413d0f82425aaa28fb288009bf0d0964711d347763af2f1b65cafcb028c82"},
-    {file = "sphinx_rtd_theme-0.5.0.tar.gz", hash = "sha256:22c795ba2832a169ca301cd0a083f7a434e09c538c70beb42782c073651b707d"},
+    {file = "sphinx_rtd_theme-1.0.0-py2.py3-none-any.whl", hash = "sha256:4d35a56f4508cfee4c4fb604373ede6feae2a306731d533f409ef5c3496fdbd8"},
+    {file = "sphinx_rtd_theme-1.0.0.tar.gz", hash = "sha256:eec6d497e4c2195fa0e8b2016b337532b8a699a68bcb22a512870e16925c6a5c"},
 ]
 sphinxcontrib-applehelp = [
     {file = "sphinxcontrib-applehelp-1.0.1.tar.gz", hash = "sha256:edaa0ab2b2bc74403149cb0209d6775c96de797dfd5b5e2a71981309efab3897"},
diff --git a/pyproject.toml b/pyproject.toml
index 7a5815f..d3fc84b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ pytest-runner = "^5.3"
 towncrier = {version = "^19.2", optional = true}
 tox = "^3.19"
 sphinx = {version = "^3.1", optional = true}
-sphinx_rtd_theme = {version = "^0.5.0", optional = true}
+sphinx_rtd_theme = {version = "^1.0.0", optional = true}
 pre-commit = {version = "^2.1", optional = true}
 
 [tool.poetry.extras]