diff --git a/lib/less/tree/mixin.js b/lib/less/tree/mixin.js
index d0496e1b..17a4e672 100644
--- a/lib/less/tree/mixin.js
+++ b/lib/less/tree/mixin.js
@@ -10,7 +10,7 @@ tree.mixin.Call = function (elements, args, index, filename, important) {
 };
 tree.mixin.Call.prototype = {
     eval: function (env) {
-        var mixins, args, rules = [], match = false, i, m, f, isRecursive, isOneFound;
+        var mixins, mixin, args, rules = [], match = false, i, m, f, isRecursive, isOneFound;
 
         args = this.arguments && this.arguments.map(function (a) {
             return { name: a.name, value: a.value.eval(env) };
@@ -20,9 +20,10 @@ tree.mixin.Call.prototype = {
             if ((mixins = env.frames[i].find(this.selector)).length > 0) {
                 isOneFound = true;
                 for (m = 0; m < mixins.length; m++) {
+                    mixin = mixins[m];
                     isRecursive = false;
                     for(f = 0; f < env.frames.length; f++) {
-                        if ((!(mixins[m] instanceof tree.mixin.Definition)) && mixins[m] === (env.frames[f].originalRuleset || env.frames[f])) {
+                        if ((!(mixin instanceof tree.mixin.Definition)) && mixin === (env.frames[f].originalRuleset || env.frames[f])) {
                             isRecursive = true;
                             break;
                         }
@@ -30,14 +31,16 @@ tree.mixin.Call.prototype = {
                     if (isRecursive) {
                         continue;
                     }
-                    if (mixins[m].match(args, env)) {
-                        try {
-                            Array.prototype.push.apply(
-                                  rules, mixins[m].eval(env, this.arguments, this.important).rules);
-                            match = true;
-                        } catch (e) {
-                            throw { message: e.message, index: this.index, filename: this.filename, stack: e.stack };
+                    if (mixin.matchArgs(args, env)) {
+                        if (!mixin.matchCondition || mixin.matchCondition(args, env)) {
+                            try {
+                                Array.prototype.push.apply(
+                                      rules, mixin.eval(env, this.arguments, this.important).rules);
+                            } catch (e) {
+                                throw { message: e.message, index: this.index, filename: this.filename, stack: e.stack };
+                            }
                         }
+                        match = true;
                     }
                 }
                 if (match) {
@@ -167,7 +170,13 @@ tree.mixin.Definition.prototype = {
         ruleset.originalRuleset = this;
         return ruleset;
     },
-    match: function (args, env) {
+    matchCondition: function (args, env) {
+        if (this.condition && !this.condition.eval({
+            frames: [this.evalParams(env, args, [])].concat(env.frames)
+        }))                                                           { return false }
+        return true;
+    },
+    matchArgs: function (args, env) {
         var argsLength = (args && args.length) || 0, len, frame;
 
         if (! this.variadic) {
@@ -176,10 +185,6 @@ tree.mixin.Definition.prototype = {
             if ((this.required > 0) && (argsLength > this.params.length)) { return false }
         }
 
-        if (this.condition && !this.condition.eval({
-            frames: [this.evalParams(env, args, [])].concat(env.frames)
-        }))                                                           { return false }
-
         len = Math.min(argsLength, this.arity);
 
         for (var i = 0; i < len; i++) {
diff --git a/lib/less/tree/ruleset.js b/lib/less/tree/ruleset.js
index 71402aac..8ac4811a 100644
--- a/lib/less/tree/ruleset.js
+++ b/lib/less/tree/ruleset.js
@@ -85,7 +85,7 @@ tree.Ruleset.prototype = {
                     }
                 }), this.strictImports);
     },
-    match: function (args) {
+    matchArgs: function (args) {
         return !args || args.length === 0;
     },
     variables: function () {
diff --git a/test/less/mixins-guards.less b/test/less/mixins-guards.less
index c92b34d5..4414e326 100644
--- a/test/less/mixins-guards.less
+++ b/test/less/mixins-guards.less
@@ -99,8 +99,6 @@
 .equality-unit-test(@num) when (@num = 2) {
   test: pass;
 }
-.equality-unit-test(@num) {
-}
 .equality-units {
   .equality-unit-test(1px);
   .equality-unit-test(2px);