diff --git a/lib/ast.js b/lib/ast.js
index e61a31e5..962c8f7b 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -619,7 +619,7 @@ var AST_UnaryPostfix = DEFNODE("UnaryPostfix", null, {
     $documentation: "Unary postfix expression, i.e. `i++`"
 }, AST_Unary);
 
-var AST_Binary = DEFNODE("Binary", "left operator right", {
+var AST_Binary = DEFNODE("Binary", "operator left right", {
     $documentation: "Binary expression, i.e. `a + b`",
     $propdoc: {
         left: "[AST_Node] left-hand side expression",