diff --git a/CHANGELOG.md b/CHANGELOG.md
index f82a5f2..a8977ad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,5 @@
 ### HEAD
+* Make sure rewrites are added to .htaccess immediately after activation
 * Move HTML5 Boilerplate's .htaccess to a [plugin](https://github.com/retlehs/wp-h5bp-htaccess)
 * Rename page-custom.php to template-custom.php
 * Don't warn about unwritable htaccess if that option is disabled
diff --git a/lib/activation.php b/lib/activation.php
index ce8add8..d675f1e 100644
--- a/lib/activation.php
+++ b/lib/activation.php
@@ -38,8 +38,7 @@ function roots_theme_activation_options_add_page() {
     );
   } else {
     if (is_admin() && isset($_GET['page']) && $_GET['page'] === 'theme_activation_options') {
-      global $wp_rewrite;
-      $wp_rewrite->flush_rules();
+      flush_rewrite_rules();
       wp_redirect(admin_url('themes.php'));
       exit;
     }
@@ -217,14 +216,12 @@ function roots_theme_activation_action() {
 
   if ($roots_theme_activation_options['change_permalink_structure']) {
     $roots_theme_activation_options['change_permalink_structure'] = false;
-    global $wp_rewrite;
 
     if (get_option('permalink_structure') !== '/%postname%/') {
+      global $wp_rewrite;
       $wp_rewrite->set_permalink_structure('/%postname%/');
+      flush_rewrite_rules();
     }
-
-    $wp_rewrite->init();
-    $wp_rewrite->flush_rules();
   }
 
   if ($roots_theme_activation_options['change_uploads_folder']) {
diff --git a/lib/rewrites.php b/lib/rewrites.php
index e2db26d..f13a2b0 100644
--- a/lib/rewrites.php
+++ b/lib/rewrites.php
@@ -35,7 +35,7 @@ function roots_clean_urls($content) {
   }
 }
 
-if (!is_multisite() && !is_child_theme() && get_option('permalink_structure')) {
+if (!is_multisite() && !is_child_theme()) {
   if (current_theme_supports('rewrites')) {
     add_action('generate_rewrite_rules', 'roots_add_rewrites');
   }