diff --git a/.travis.yml b/.travis.yml
index 0aad9a3..b5b0111 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,12 +2,17 @@ sudo: false
 language: php
 cache: npm
 php:
-  - 5.6
-  - 5.5
-  - 5.4
+- '5.6'
+- '5.5'
+- '5.4'
+
 before_install:
   - npm install -g bower
   - npm install
+  - pyrus install pear/PHP_CodeSniffer
+  - phpenv rehash
+
 script:
   - npm run build
   - npm run jshint
+  - phpcs --standard=ruleset.xml --extensions=php -n -s .
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7057ec2..c4ae76f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ### 8.0.0: TBD
 * Change theme name from Roots to Sage
 * Bump required PHP version to >=5.4
+* Add coding standards based on PSR-2
 * Add namespace
 * Use short array syntax
 * Use short echo syntax
diff --git a/base.php b/base.php
index 80bb5fc..5bab6b1 100644
--- a/base.php
+++ b/base.php
@@ -1,8 +1,10 @@
 <?php
 
 namespace Roots\Sage;
+
 use Roots\Sage\Config;
 use Roots\Sage\Wrapper;
+
 ?>
 
 <?php get_template_part('templates/head'); ?>
diff --git a/lib/assets.php b/lib/assets.php
index 553f660..23996a9 100644
--- a/lib/assets.php
+++ b/lib/assets.php
@@ -93,7 +93,7 @@ function google_analytics() {
       e=o.createElement(i);r=o.getElementsByTagName(i)[0];
       e.src='//www.google-analytics.com/analytics.js';
       r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));
-    <?php else: ?>
+    <?php else : ?>
       function ga() {
         if (window.console) {
           console.log('Google Analytics: ' + [].slice.call(arguments));
diff --git a/lib/config.php b/lib/config.php
index 6e9b735..c51d360 100644
--- a/lib/config.php
+++ b/lib/config.php
@@ -1,6 +1,7 @@
 <?php
 
 namespace Roots\Sage\Config;
+
 use Roots\Sage\Sidebar;
 
 /**
@@ -41,7 +42,7 @@ function display_sidebar() {
   static $display;
 
   if (!isset($display)) {
-    $sidebar_config = new Sidebar\Sage_Sidebar(
+    $sidebar_config = new Sidebar\SageSidebar(
       /**
        * Conditional tag checks (http://codex.wordpress.org/Conditional_Tags)
        * Any of these conditional tags that return true won't show the sidebar
diff --git a/lib/nav.php b/lib/nav.php
index bfcf9dd..d9ca69d 100644
--- a/lib/nav.php
+++ b/lib/nav.php
@@ -9,15 +9,16 @@ namespace Roots\Sage\Nav;
  *   <li id="menu-item-8" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-8"><a href="/">Home</a></li>
  *   <li id="menu-item-9" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-9"><a href="/sample-page/">Sample Page</a></l
  *
- * Sage_Nav_Walker example output:
+ * SageNavWalker example output:
  *   <li class="menu-home"><a href="/">Home</a></li>
  *   <li class="menu-sample-page"><a href="/sample-page/">Sample Page</a></li>
  */
-class Sage_Nav_Walker extends \Walker_Nav_Menu {
-  function check_current($classes) {
+class SageNavWalker extends \Walker_Nav_Menu {
+  public function checkCurrent($classes) {
     return preg_match('/(current[-_])|active|dropdown/', $classes);
   }
 
+  // @codingStandardsIgnoreStart
   function start_lvl(&$output, $depth = 0, $args = []) {
     $output .= "\n<ul class=\"dropdown-menu\">\n";
   }
@@ -29,11 +30,9 @@ class Sage_Nav_Walker extends \Walker_Nav_Menu {
     if ($item->is_dropdown && ($depth === 0)) {
       $item_html = str_replace('<a', '<a class="dropdown-toggle" data-toggle="dropdown" data-target="#"', $item_html);
       $item_html = str_replace('</a>', ' <b class="caret"></b></a>', $item_html);
-    }
-    elseif (stristr($item_html, 'li class="divider')) {
+    } elseif (stristr($item_html, 'li class="divider')) {
       $item_html = preg_replace('/<a[^>]*>.*?<\/a>/iU', '', $item_html);
-    }
-    elseif (stristr($item_html, 'li class="dropdown-header')) {
+    } elseif (stristr($item_html, 'li class="dropdown-header')) {
       $item_html = preg_replace('/<a[^>]*>(.*)<\/a>/iU', '$1', $item_html);
     }
 
@@ -50,6 +49,7 @@ class Sage_Nav_Walker extends \Walker_Nav_Menu {
 
     parent::display_element($element, $children_elements, $max_depth, $depth, $args, $output);
   }
+  // @codingStandardsIgnoreEnd
 }
 
 /**
@@ -82,7 +82,7 @@ add_filter('nav_menu_item_id', '__return_null');
  * Clean up wp_nav_menu_args
  *
  * Remove the container
- * Use Sage_Nav_Walker() by default
+ * Use SageNavWalker() by default
  */
 function nav_menu_args($args = '') {
   $nav_menu_args = [];
diff --git a/lib/sidebar.php b/lib/sidebar.php
index 5a976ed..c1f9699 100644
--- a/lib/sidebar.php
+++ b/lib/sidebar.php
@@ -14,25 +14,25 @@ namespace Roots\Sage\Sidebar;
  *
  * @return boolean True will display the sidebar, False will not
  */
-class Sage_Sidebar {
+class SageSidebar {
   private $conditionals;
   private $templates;
 
   public $display = true;
 
-  function __construct($conditionals = [], $templates = []) {
+  public function __construct($conditionals = [], $templates = []) {
     $this->conditionals = $conditionals;
     $this->templates    = $templates;
 
-    $conditionals = array_map([$this, 'check_conditional_tag'], $this->conditionals);
-    $templates    = array_map([$this, 'check_page_template'], $this->templates);
+    $conditionals = array_map([$this, 'checkConditionalTag'], $this->conditionals);
+    $templates    = array_map([$this, 'checkPageTemplate'], $this->templates);
 
     if (in_array(true, $conditionals) || in_array(true, $templates)) {
       $this->display = false;
     }
   }
 
-  private function check_conditional_tag($conditional_tag) {
+  private function checkConditionalTag($conditional_tag) {
     $conditional_arg = is_array($conditional_tag) ? $conditional_tag[1] : false;
     $conditional_tag = $conditional_arg ? $conditional_tag[0] : $conditional_tag;
 
@@ -43,7 +43,7 @@ class Sage_Sidebar {
     }
   }
 
-  private function check_page_template($page_template) {
+  private function checkPageTemplate($page_template) {
     return is_page_template($page_template);
   }
 }
diff --git a/lib/wrapper.php b/lib/wrapper.php
index 4b4c904..cb3b6d0 100644
--- a/lib/wrapper.php
+++ b/lib/wrapper.php
@@ -10,14 +10,14 @@ namespace Roots\Sage\Wrapper;
  */
 
 function template_path() {
-  return Sage_Wrapping::$main_template;
+  return SageWrapping::$main_template;
 }
 
 function sidebar_path() {
-  return new Sage_Wrapping('templates/sidebar.php');
+  return new SageWrapping('templates/sidebar.php');
 }
 
-class Sage_Wrapping {
+class SageWrapping {
   // Stores the full path to the main template file
   public static $main_template;
 
@@ -28,7 +28,7 @@ class Sage_Wrapping {
   public $templates;
 
   // Stores the base name of the template file; e.g. 'page' for 'page.php' etc.
-  static $base;
+  public static $base;
 
   public function __construct($template = 'base.php') {
     $this->slug = basename($template, '.php');
@@ -45,7 +45,7 @@ class Sage_Wrapping {
     return locate_template($this->templates);
   }
 
-  static function wrap($main) {
+  public static function wrap($main) {
     // Check for other filters returning null
     if (!is_string($main)) {
       return $main;
@@ -58,7 +58,7 @@ class Sage_Wrapping {
       self::$base = false;
     }
 
-    return new Sage_Wrapping();
+    return new SageWrapping();
   }
 }
-add_filter('template_include', [__NAMESPACE__ . '\\Sage_Wrapping', 'wrap'], 99);
+add_filter('template_include', [__NAMESPACE__ . '\\SageWrapping', 'wrap'], 99);
diff --git a/ruleset.xml b/ruleset.xml
new file mode 100644
index 0000000..3ae92ca
--- /dev/null
+++ b/ruleset.xml
@@ -0,0 +1,45 @@
+<?xml version="1.0"?>
+<ruleset name="Roots">
+  <description>Roots Coding Standards</description>
+
+  <!-- Use PSR-2 as a base -->
+  <rule ref="PSR2">
+    <!-- Allow closing braces for functions and classes to be on the same line -->
+    <exclude name="Squiz.Functions.MultiLineFunctionDeclaration.BraceOnSameLine"/>
+    <exclude name="PSR2.Classes.ClassDeclaration.OpenBraceNewLine"/>
+    <exclude name="Squiz.WhiteSpace.ScopeClosingBrace"/>
+
+    <!-- Disable newline after opening brace -->
+    <exclude name="Squiz.ControlStructures.ControlSignature.NewlineAfterOpenBrace"/>
+
+    <!-- Allow multiple PHP statements in the same line (usually in template files) -->
+    <exclude name="Generic.Formatting.DisallowMultipleStatements.SameLine"/>
+
+    <!-- Disable PSR-2 indentation rules that are buggy with 2 spaces -->
+    <exclude name="PSR2.ControlStructures.SwitchDeclaration.BreakIndent"/>
+    <exclude name="PSR2.Methods.FunctionCallSignature.Indent"/>
+  </rule>
+
+  <!-- Don't require a blank line after the last `use` in templates/ directory -->
+  <rule ref="PSR2.Namespaces.UseDeclaration.SpaceAfterLastUse">
+    <exclude-pattern>templates/*</exclude-pattern>
+  </rule>
+
+  <!-- Allow PHP closing tags on templates -->
+  <rule ref="Zend.Files.ClosingTag.NotAllowed">
+    <exclude-pattern>templates/*</exclude-pattern>
+    <exclude-pattern>404.php</exclude-pattern>
+    <exclude-pattern>index.php</exclude-pattern>
+    <exclude-pattern>page.php</exclude-pattern>
+    <exclude-pattern>single.php</exclude-pattern>
+    <exclude-pattern>template-custom.php</exclude-pattern>
+  </rule>
+
+  <!-- Force 2 spaces indentation -->
+  <rule ref="Generic.WhiteSpace.ScopeIndent">
+    <properties>
+      <property name="indent" value="2"/>
+      <property name="tabIndent" value="false"/>
+    </properties>
+  </rule>
+</ruleset>
diff --git a/templates/comments.php b/templates/comments.php
index 5452fa2..167a4d1 100644
--- a/templates/comments.php
+++ b/templates/comments.php
@@ -1,7 +1,7 @@
 <?php
-  if (post_password_required()) {
-    return;
-  }
+if (post_password_required()) {
+  return;
+}
 ?>
 
 <section id="comments" class="comments">
diff --git a/templates/header.php b/templates/header.php
index 8ad5cc5..010379a 100644
--- a/templates/header.php
+++ b/templates/header.php
@@ -14,9 +14,9 @@
 
     <nav class="collapse navbar-collapse" role="navigation">
       <?php
-        if (has_nav_menu('primary_navigation')) :
-          wp_nav_menu(['theme_location' => 'primary_navigation', 'walker' => new Nav\Sage_Nav_Walker(), 'menu_class' => 'nav navbar-nav']);
-        endif;
+      if (has_nav_menu('primary_navigation')) :
+        wp_nav_menu(['theme_location' => 'primary_navigation', 'walker' => new Nav\SageNavWalker(), 'menu_class' => 'nav navbar-nav']);
+      endif;
       ?>
     </nav>
   </div>