diff --git a/pyproject.toml b/pyproject.toml
index 69c39ca..cc7c347 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,6 +26,8 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Natural Language :: English",
     "Topic :: Scientific/Engineering :: Bio-Informatics",
     "Topic :: Software Development :: Libraries",
     "Typing :: Typed",