diff --git a/.jshintrc b/.jshintrc
new file mode 100644
index 0000000..84e9e31
--- /dev/null
+++ b/.jshintrc
@@ -0,0 +1,23 @@
+{
+  "asi": true,
+  "curly": false,
+  "eqeqeq": false,
+  "eqnull": true,
+  "immed": true,
+  "latedef": "nofunc",
+  "laxbreak": true,
+  "mocha" : true,
+  "newcap": true,
+  "noarg": true,
+  "browser": true,
+  "shadow": true,
+  "sub": true,
+  "undef": true,
+  "unused": true,
+  "globals": {
+    "exports": false,
+    "require": false,
+    "module": false
+  }
+
+}
diff --git a/Makefile b/Makefile
index 9b1c0db..87c59be 100644
--- a/Makefile
+++ b/Makefile
@@ -11,4 +11,7 @@ clean:
 test:
 	@./node_modules/.bin/component-test phantom
 
+lint:
+	@./node_modules/.bin/jshint index.js lib test
+
 .PHONY: clean test
diff --git a/lib/css.js b/lib/css.js
index 7137d8f..fd9b791 100644
--- a/lib/css.js
+++ b/lib/css.js
@@ -76,5 +76,5 @@ function css(el, prop, extra, styles) {
  */
 
 function isNumeric(obj) {
-  return !isNan(parseFloat(obj)) && isFinite(obj);
+  return !isNaN(parseFloat(obj)) && isFinite(obj);
 }
diff --git a/lib/hooks.js b/lib/hooks.js
index 7468ab2..c41d774 100644
--- a/lib/hooks.js
+++ b/lib/hooks.js
@@ -32,9 +32,9 @@ each(['width', 'height'], function(name) {
   }
 
   exports[name].set = function(el, val, extra) {
-    var styles = extra && styles(el);
+    var elStyles = extra && styles(el);
     return setPositiveNumber(el, val, extra
-      ? augmentWidthOrHeight(el, name, extra, 'border-box' == css(el, 'boxSizing', false, styles), styles)
+      ? augmentWidthOrHeight(el, name, extra, 'border-box' == css(el, 'boxSizing', false, elStyles), elStyles)
       : 0
     );
   };
diff --git a/lib/prop.js b/lib/prop.js
index 6abd9a0..4864525 100644
--- a/lib/prop.js
+++ b/lib/prop.js
@@ -3,7 +3,6 @@
  */
 
 var debug = require('debug')('css:prop');
-var camelcase = require('to-camel-case');
 var vendor = require('./vendor');
 
 /**
diff --git a/lib/swap.js b/lib/swap.js
index b9b9942..8547173 100644
--- a/lib/swap.js
+++ b/lib/swap.js
@@ -15,6 +15,8 @@ module.exports = swap;
  */
 
 function swap(el, options, fn, args) {
+  var old = {}, ret;
+
   // Remember the old values, and insert the new ones
   for (var key in options) {
     old[key] = el.style[key];
diff --git a/package.json b/package.json
index c326036..c769502 100644
--- a/package.json
+++ b/package.json
@@ -10,9 +10,10 @@
     "component-each": "~0.2.2"
   },
   "devDependencies": {
+    "component-test2": "*",
     "domify": "^1.2.2",
-    "load-styles": "^1.0.1",
-    "component-test2": "*"
+    "jshint": "^2.7.0",
+    "load-styles": "^1.0.1"
   },
   "browser": {
     "each": "component-each"