diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a420a2ee..2a4a6ed8 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -26,14 +26,14 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         python-version: [3.7, 3.8, 3.9]
-        sphinx: [">=3,<4", ">=4,<5"]
+        sphinx: [">=4,<5", ">=5,<6"]
         include:
         - os: windows-latest
           python-version: 3.9
-          sphinx: ">=3,<4"
+          sphinx: ">=4,<5"
         - os: macos-latest
           python-version: 3.9
-          sphinx: ">=4,<5"
+          sphinx: ">=5,<6"
     runs-on: ${{ matrix.os }}
 
     steps:
diff --git a/pyproject.toml b/pyproject.toml
index b67a834a..1d3ff833 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,7 +22,7 @@ readme = "README.md"
 
 requires-python = ">=3.7"
 dependencies = [
-  "sphinx>=3,<6",
+  "sphinx>=4,<6",
   "pydata-sphinx-theme~=0.10.1",
   "pyyaml",
 ]