diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1e2df7d..2b6bcf5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -15,7 +15,7 @@ jobs:
       max-parallel: 4
       matrix:
         python-version: [3.6, 3.7, 3.8, 3.9, '3.10']
-        sphinx-version: ['>=3.0.0,<4.0.0', '>=4.0.0,<5.0.0', '>=5.0.0,<6.0.0']
+        sphinx-version: ['>=3.0.0,<4.0.0', '>=4.0.0,<5.0.0', '>=5.0.0,<5.1.0', '>=5.1.0,<6.0.0']
         exclude:
           # Old major version does not support python 3.10
           - python-version: '3.10'
diff --git a/sphinx_revealjs/builders.py b/sphinx_revealjs/builders.py
index 7bc94e9..7135d6a 100644
--- a/sphinx_revealjs/builders.py
+++ b/sphinx_revealjs/builders.py
@@ -31,8 +31,8 @@ class RevealjsHTMLBuilder(StandaloneHTMLBuilder):
     search = False
 
     def __init__(self, app, env: BuildEnvironment = None):  # noqa: D107
-        # TODO: Remove it if this not need support Sphinx 4.x and older
-        if sphinx_versoin[0] < 5:
+        # TODO: Remove it if this not need support Sphinx 5.1.0 and older
+        if sphinx_versoin[0] <= 4 or sphinx_versoin[:2] == (5, 0):
             super().__init__(app)
         else:
             super().__init__(app, env)