diff --git a/crates/lang/src/ast.rs b/crates/lang/src/ast.rs
new file mode 100644
index 00000000..5541619b
--- /dev/null
+++ b/crates/lang/src/ast.rs
@@ -0,0 +1,5 @@
+pub struct Module {}
+
+pub enum Decl {}
+
+pub enum Expr {}
diff --git a/crates/lang/src/lib.rs b/crates/lang/src/lib.rs
index 1b4a90c9..660c3de9 100644
--- a/crates/lang/src/lib.rs
+++ b/crates/lang/src/lib.rs
@@ -1,3 +1,5 @@
+pub mod ast;
+
 #[cfg(test)]
 mod tests {
     #[test]