diff --git a/pyproject.toml b/pyproject.toml
index 4a4d93f7..c08d5f58 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -46,7 +46,7 @@ test = [
 ]
 docs = [
     "pyemu[optional]",
-    "sphinx >=3.2.1",
+    "sphinx <7.2",  # sphinx 7.2 challenges with iterating over CSS
     "sphinx-autoapi",
     "sphinx-rtd-theme >=1.3.0rc1",
 ]