diff --git a/pyproject.toml b/pyproject.toml
index e2fb466..ee5dc98 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
 # Minimum requirements for the build system to execute.
-requires = ["setuptools", "numpy>=1.13.0", "wheel"]  # PEP 508 specifications.
+requires = ["setuptools", "oldest-supported-numpy", "wheel"]  # PEP 508 specifications.