diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 1e2a374a..9254d49c 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -32,7 +32,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install urwid twisted watchdog "jedi >=0.16" babel "sphinx >=1.5"
+        pip install urwid twisted watchdog "jedi >=0.16" babel "sphinx >=1.5,<7"
         pip install pytest pytest-cov numpy
     - name: Build with Python ${{ matrix.python-version }}
       run: |
diff --git a/setup.py b/setup.py
index 6790b9d7..7ca279d3 100755
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@
     from sphinx.setup_command import BuildDoc
 
     # Sphinx 1.5 and newer support Python 3.6
-    using_sphinx = sphinx.__version__ >= "1.5"
+    using_sphinx = sphinx.__version__ >= "1.5" and sphinx.__version__ < "7.0"
 except ImportError:
     using_sphinx = False