diff --git a/pyproject.toml b/pyproject.toml
index d8e9391..11e02dc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,9 @@ description = ""
 authors = ["Erik Harding <erik@praekelt.org>"]
 readme = "README.md"
 repository = "https://github.com/praekeltfoundation/mc-intent-classifier"
-package-mode = false
+packages = [
+    { include = "src" },
+]
 
 [tool.poetry.dependencies]
 python = "^3.11"