diff --git a/lib/ast.js b/lib/ast.js
index ae10abdf..7ae3a114 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -425,13 +425,8 @@ var AST_ArrowParametersOrSeq = DEFNODE("ArrowParametersOrSeq", "expressions", {
                     default: default_seen_above,
                     names: ex.elements.map(to_fun_args)
                 });
-            } else if (ex instanceof AST_Assign && ex.left instanceof AST_Symbol) {
-                return new AST_SymbolFunarg({
-                    name: ex.left.name,
-                    default: ex.right,
-                    start: ex.start,
-                    end: ex.end
-                });
+            } else if (ex instanceof AST_Assign) {
+                return to_fun_args(ex.left, undefined, undefined, ex.right);
             } else {
                 croak("Invalid function parameter", ex.start.line, ex.start.col);
             }