diff --git a/system/htmly.php b/system/htmly.php
index 9e65ee3..a4591e9 100644
--- a/system/htmly.php
+++ b/system/htmly.php
@@ -1547,10 +1547,11 @@ get('/search/:keyword', function ($keyword) {
         // a non-existing page or no search result
         render('404-search', array(
             'title' => 'Search results not found! - ' . blog_title(),
-            'description' => '',
+            'description' => 'Search results not found!',
             'breadcrumb' => '<a href="' . site_url() . '">' . config('breadcrumb.home') . '</a> &#187; No search results',
-            'canonical' => site_url() . 'search/' . strtolower($keyword),
+            'canonical' => site_url(),
             'bodyclass' => 'error-404-search',
+            'is_search' => is_search(true),
         ));
         die;
     }
diff --git a/system/includes/functions.php b/system/includes/functions.php
index d169764..f2f1d13 100644
--- a/system/includes/functions.php
+++ b/system/includes/functions.php
@@ -812,7 +812,8 @@ function get_keyword($keyword, $page, $perpage)
         }
     }
 
-    return ($tmp) ? get_posts($tmp, $page, $perpage) : [];
+    return ($tmp) ? get_posts($tmp, $page, $perpage) : []; 
+ 
 }
 
 // Get related posts base on post tag.
@@ -899,8 +900,7 @@ function get_categorycount($var)
 
         // Author string
         $str = explode('/', $replaced);
-        $cat = $str[count($str) - 3];
-        
+        $cat = '/blog/' . $str[count($str) - 3];
         if (stripos($cat, "$var") !== false) {
             $tmp[] = $v;
         }
@@ -1755,10 +1755,11 @@ function not_found()
     header($_SERVER["SERVER_PROTOCOL"] . " 404 Not Found");
     render('404', array(
         'title' => 'This page doesn\'t exist! - ' . blog_title(),
-        'description' => '',
-        'canonical' => false,
+        'description' => '404 Not Found',
+        'canonical' => site_url(),
         'breadcrumb' => '<a href="' . site_url() . '">' . config('breadcrumb.home') . '</a> &#187; 404 Not Found',
         'bodyclass' => 'error-404',
+        'is_notfound' => is_notfound(true),
     ));
     die();
 }
@@ -2275,6 +2276,16 @@ function is_subpage($value = null)
     }
 }
 
+// TRUE if the current page is 404 error page.
+function is_notfound($value = null)
+{
+    if (!empty($value)) {
+        return true;
+    } else {
+        return false;
+    }
+}
+
 // Return blog title
 function blog_title()
 {
diff --git a/themes/blog/layout.html.php b/themes/blog/layout.html.php
index 4b8dd74..d2ca1b9 100644
--- a/themes/blog/layout.html.php
+++ b/themes/blog/layout.html.php
@@ -6,9 +6,7 @@
     <?php echo head_contents();?>
     <title><?php echo $title;?></title>
     <meta name="description" content="<?php echo $description; ?>"/>
-    <?php if($canonical): ?>
-        <link rel="canonical" href="<?php echo $canonical; ?>" />
-    <?php endif; ?>
+    <link rel="canonical" href="<?php echo $canonical; ?>" />
     <?php if (publisher()): ?>
     <link href="<?php echo publisher() ?>" rel="publisher" /><?php endif; ?>    
     <link href="//fonts.googleapis.com/css?family=Lato:300,400,300italic,400italic" rel="stylesheet" type="text/css">
diff --git a/themes/clean/layout.html.php b/themes/clean/layout.html.php
index 5017490..38d5377 100644
--- a/themes/clean/layout.html.php
+++ b/themes/clean/layout.html.php
@@ -4,9 +4,7 @@
     <?php echo head_contents() ?>
     <title><?php echo $title;?></title>
     <meta name="description" content="<?php echo $description; ?>"/>
-    <?php if($canonical): ?>
-        <link rel="canonical" href="<?php echo $canonical; ?>" />
-    <?php endif; ?>
+    <link rel="canonical" href="<?php echo $canonical; ?>" />
     <link href="<?php echo site_url() ?>themes/clean/css/style.css" rel="stylesheet"/>
     <link href="//fonts.googleapis.com/css?family=Open+Sans+Condensed:700&subset=latin,cyrillic-ext" rel="stylesheet"/>
     <?php if (publisher()): ?>
diff --git a/themes/default/layout.html.php b/themes/default/layout.html.php
index bbb8ef8..754f78a 100644
--- a/themes/default/layout.html.php
+++ b/themes/default/layout.html.php
@@ -4,9 +4,7 @@
     <?php echo head_contents() ?>
     <title><?php echo $title;?></title>
     <meta name="description" content="<?php echo $description; ?>"/>
-    <?php if($canonical): ?>
-        <link rel="canonical" href="<?php echo $canonical; ?>" />
-    <?php endif; ?>
+    <link rel="canonical" href="<?php echo $canonical; ?>" />
     <link href="<?php echo site_url() ?>themes/default/css/style.css" rel="stylesheet"/>
     <link href="//fonts.googleapis.com/css?family=Open+Sans:400,700" rel="stylesheet" type="text/css">
     <?php if (publisher()): ?>
diff --git a/themes/logs/layout.html.php b/themes/logs/layout.html.php
index 056e6ad..966988c 100644
--- a/themes/logs/layout.html.php
+++ b/themes/logs/layout.html.php
@@ -4,9 +4,7 @@
     <?php echo head_contents() ?>
     <title><?php echo $title;?></title>
     <meta name="description" content="<?php echo $description; ?>"/>
-    <?php if($canonical): ?>
-        <link rel="canonical" href="<?php echo $canonical; ?>" />
-    <?php endif; ?>
+    <link rel="canonical" href="<?php echo $canonical; ?>" />
     <link href="<?php echo site_url() ?>themes/logs/css/style.css" rel="stylesheet"/>
     <link href="//fonts.googleapis.com/css?family=Open+Sans:400,700" rel="stylesheet" type="text/css">
     <?php if (publisher()): ?>