diff --git a/pyproject.toml b/pyproject.toml
index b3009ac2..82683189 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -66,7 +66,7 @@ dev = [
     "zest.releaser>=6.20.1",
 ]
 doc = [
-    "Sphinx>=7.0.1,<8",
+    "Sphinx>=7.0.1,<9",
     "docutils==0.20.1",
     "myst-parser>=2,<3",
 ]