diff --git a/pyproject.toml b/pyproject.toml
index c51d63a..58bf509 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@
 # work.  If not, see <https://creativecommons.org/licenses/by-nc-sa/4.0/>.
 
 [build-system]
-requires = ["setuptools>=63", "wheel", "setuptools_scm"]
+requires = ["setuptools>=63", "wheel", "setuptools_scm","frozendict","typeguard"]
 build-backend = "setuptools.build_meta"
 
 [tool.setuptools_scm]