diff --git a/tests/mod.rs b/tests/mod.rs
index 6b81324..31e9492 100644
--- a/tests/mod.rs
+++ b/tests/mod.rs
@@ -1,4 +1,8 @@
+//! Integration tests.
+
+/// Tests for programming languages.
 #[cfg(test)]
 mod langs;
 #[cfg(test)]
+/// Property testing (where applicable and useful).
 mod properties;