diff --git a/accelerate/src/vbo.pyx b/accelerate/src/vbo.pyx
index 13f9e99d..6e92c059 100644
--- a/accelerate/src/vbo.pyx
+++ b/accelerate/src/vbo.pyx
@@ -1,6 +1,7 @@
 """Cython-coded VBO implementation"""
 #cython: language_level=3
 import ctypes, weakref
+from ctypes import c_long as long
 from OpenGL_accelerate.formathandler cimport FormatHandler
 from OpenGL import error
 from OpenGL._bytes import bytes,unicode
diff --git a/pyproject.toml b/pyproject.toml
index 9f95e22f..9be113e4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,7 +36,7 @@ Source = "https://github.com/mcfletch/pyopengl"
 Documentation = "https://mcfletch.github.io/pyopengl/documentation/index.html"
 
 [build-system]
-requires = [ "setuptools >= 42.0" ]
+requires = [ "setuptools >= 42.0", "cython>=3.0.0" ]
 build-backend = "setuptools.build_meta"
 
 [tool.setuptools.dynamic]