diff --git a/pyproject.toml b/pyproject.toml
index 1229a73a..d6cc581c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,6 +19,7 @@ authors = [
 description = "Python binding to the Networking and Cryptography (NaCl) library"
 license = {text = "Apache-2.0"}
 classifiers = [
+    "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Programming Language :: Python :: 3",