diff --git a/pyproject.toml b/pyproject.toml
index 1be9809..4102cd0 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,6 +19,7 @@ dynamic = ["version"]
 dependencies = [
     "frozendict",
     "numpy",
+    "protobuf",
 
     # CLI
     "rich",