diff --git a/pyproject.toml b/pyproject.toml
index 38cf08b..d5f3803 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -73,7 +73,7 @@ urllib3 = ">=1.22.0,<3"
 optional = true
 
 [tool.poetry.group.docs.dependencies]
-sphinx = "^6.0.0"
+sphinx = ">=6,<8"
 sphinx-rtd-theme = ">=1.3,<3.0"
 certifi = ">=2018.4.16"
 expiringdict = ">=1.1.4"