diff --git a/.jscsrc b/.jscsrc
index a54fd6d2..07bd2255 100644
--- a/.jscsrc
+++ b/.jscsrc
@@ -4,6 +4,7 @@
     "requireCapitalizedConstructors": false,
     "disallowTrailingWhitespace": "ignoreEmptyLines",
     "disallowTrailingComma": false,
+    "disallowUnusedVariables": true,
     "validateIndentation": false,
     "requireCurlyBraces": false,
     "requireSpacesInAnonymousFunctionExpression": {
diff --git a/lib/client/dom.js b/lib/client/dom.js
index dd9b62f7..592cbedb 100644
--- a/lib/client/dom.js
+++ b/lib/client/dom.js
@@ -796,7 +796,7 @@ var CloudCmd, Util, DOM, CloudFunc;
              * unified way to set current file
              */
             this.setCurrentFile          = function(currentFile, options) {
-                var ret, path, pathWas, title,
+                var path, pathWas, title,
                     o               = options,
                     FS              = CloudFunc.FS,
                     CENTER          = true,
@@ -831,8 +831,6 @@ var CloudCmd, Util, DOM, CloudFunc;
                     /* scrolling to current file */
                     this.scrollIntoViewIfNeeded(currentFile, CENTER);
                     
-                    ret = true;
-                    
                     Cmd.updateCurrentInfo();
                 }
                 
diff --git a/lib/client/load.js b/lib/client/load.js
index 6582a240..d071aa76 100644
--- a/lib/client/load.js
+++ b/lib/client/load.js
@@ -246,7 +246,7 @@
                         emitter.emit('end');
                     } else {
                         error = Error(xhr.responseText);
-                        emitter.emit('error');
+                        emitter.emit('error', error);
                     }
             };
             
diff --git a/lib/client/operation.js b/lib/client/operation.js
index 2f0c5a7f..1c978f52 100644
--- a/lib/client/operation.js
+++ b/lib/client/operation.js
@@ -240,7 +240,7 @@
          * @currentFile
          */
         function promptDelete() {
-            var ret, type, isDir, msg,
+            var type, isDir, msg,
                 name        = '',
                 msgAsk      = 'Do you really want to delete the ',
                 msgSel      = 'selected ',
@@ -278,8 +278,6 @@
                 Dialog.confirm(TITLE, msg, {cancel: false}).then(function() {
                     deleteSilent(files);
                 });
-            
-            return ret;
         }
         
         /**
diff --git a/lib/client/polyfill.js b/lib/client/polyfill.js
index 5cc670d2..6ecc1e30 100644
--- a/lib/client/polyfill.js
+++ b/lib/client/polyfill.js
@@ -61,14 +61,10 @@ var Util, DOM, jQuery;
     
     if (!document.removeEventListener) {
         DOM.Events.remove = function(pType, pElement, pListener) {
-            var lRet;
-            
             if (!pElement)
                 pElement = window;
             
             $(pElement).unbind(pType, pListener);
-            
-            return lRet;
         };
     }
     
diff --git a/package.json b/package.json
index 0418bef5..9e0a12b3 100644
--- a/package.json
+++ b/package.json
@@ -104,7 +104,7 @@
   },
   "devDependencies": {
     "coveralls": "^2.11.6",
-    "jscs": "^2.7.0",
+    "jscs": "^3.0.1",
     "jshint": "^2.8.0",
     "minor": "^1.2.2",
     "morgan": "^1.6.1",