diff --git a/pyproject.toml b/pyproject.toml
index 308ac2a..c27dca8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,7 @@
+[build-system]
+requires = ["pdm-backend"]
+build-backend = "pdm.backend"
+
 [project]
 name = "cry"
 version = "0.1"