diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 720f6cd32bdf8..5248f874a6e97 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -761,9 +761,9 @@ pub enum StmtKind {
 
     /// Expr without trailing semi-colon.
     Expr(P<Expr>),
-
+    /// Expr with a trailing semi-colon.
     Semi(P<Expr>),
-
+    /// Macro.
     Mac(P<(Mac, MacStmtStyle, ThinVec<Attribute>)>),
 }