diff --git a/pyproject.toml b/pyproject.toml
index a0dd8e61d..8d6855151 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [build-system]
 requires = [
-    "cmake<3.27",
+    "cmake<4.4",
     "deprecated",  # Because used in csp.impl.struct, which is used in autogen
     # oldest numpy 2 we can
     "numpy>=2,<2.1; python_version < '3.13'",