diff --git a/lib/less/parser.js b/lib/less/parser.js
index 57f42b81..70b1c394 100644
--- a/lib/less/parser.js
+++ b/lib/less/parser.js
@@ -766,7 +766,7 @@ less.Parser = function Parser(env) {
                             name = null;
 
                             // Variable
-                            if (arg.value.length = 1) {
+                            if (arg.value.length == 1) {
                                 var val = arg.value[0];
                                 if (val instanceof tree.Variable) {
                                     if ($(':')) {
diff --git a/lib/less/tree/mixin.js b/lib/less/tree/mixin.js
index 45948a87..b441bf3b 100644
--- a/lib/less/tree/mixin.js
+++ b/lib/less/tree/mixin.js
@@ -87,7 +87,7 @@ tree.mixin.Definition.prototype = {
                 if (this.params[i].variadic && args) {
                     varargs = [];
                     for (var j = i; j < args.length; j++) {
-                        varargs.push(args[j].eval(env));
+                        varargs.push(args[j].value.eval(env));
                     }
                     frame.rules.unshift(new(tree.Rule)(name, new(tree.Expression)(varargs).eval(env)));
                 } else if (val = (arg && arg.value) || this.params[i].value) {