diff --git a/src/lalib/fields/__init__.py b/src/lalib/fields/__init__.py
new file mode 100644
index 0000000..1db1a3b
--- /dev/null
+++ b/src/lalib/fields/__init__.py
@@ -0,0 +1 @@
+"""A collection of common fields used in linear algebra."""
diff --git a/tests/fields/__init__.py b/tests/fields/__init__.py
new file mode 100644
index 0000000..66e8480
--- /dev/null
+++ b/tests/fields/__init__.py
@@ -0,0 +1 @@
+"""Tests for the `lalib.fields` sub-package."""