diff --git a/inc/8chan-mod-pages.php b/inc/8chan-mod-pages.php
index 1474cf20..3375820a 100644
--- a/inc/8chan-mod-pages.php
+++ b/inc/8chan-mod-pages.php
@@ -317,6 +317,9 @@ FLAGS;
 			$code_tags = isset($_POST['code_tags']) ? '$config[\'additional_javascript\'][] = \'js/code_tags/run_prettify.js\';$config[\'markup\'][] = array("/\[code\](.+?)\[\/code\]/ms", "<code><pre class=\'prettyprint\' style=\'display:inline-block\'>\$1</pre></code>");' : '';
 			$katex = isset($_POST['katex']) ? '$config[\'katex\'] = true;$config[\'additional_javascript\'][] = \'js/katex/katex.min.js\'; $config[\'markup\'][] = array("/\[tex\](.+?)\[\/tex\]/ms", "<span class=\'tex\'>\$1</span>"); $config[\'additional_javascript\'][] = \'js/katex-enable.js\';' : '';
 			$user_flags = isset($_POST['user_flags']) ? "if (file_exists('$b/flags.php')) { include 'flags.php'; }\n" : '';
+			$captcha = isset($_POST['captcha']) ? 'true' : 'false';
+			$captcha_charset = base64_encode(isset($_POST['captcha_charset']) && $_POST['captcha_charset'] ? $_POST['captcha_charset'] : 'abcdefghijklmnopqrstuvwxyz');
+
 
 $oekaki_js = <<<OEKAKI
     \$config['additional_javascript'][] = 'js/jquery-ui.custom.min.js';
@@ -392,6 +395,8 @@ OEKAKI;
 \$config['blotter'] = base64_decode('$blotter');
 \$config['stylesheets']['Custom'] = 'board/$b.css';
 \$config['default_stylesheet'] = array('Custom', \$config['stylesheets']['Custom']);
+\$config['captcha']['enabled'] = $captcha;
+\$config['captcha']['extra'] = base64_decode('$captcha_charset');
 $code_tags $katex $oekaki $replace $multiimage $allow_flash $allow_pdf $user_flags
 if (\$config['disable_images'])
 	\$config['max_pages'] = 10000;
@@ -412,7 +417,11 @@ EOT;
 			openBoard($b);
 
 			// be smarter about rebuilds...only some changes really require us to rebuild all threads
-			if ($_config['blotter'] != $config['blotter'] || $_config['field_disable_name'] != $config['field_disable_name'] || $_config['show_sages'] != $config['show_sages']) {
+			if ($_config['captcha']['enabled'] != $config['captcha']['enabled']
+			 || $_config['captcha']['extra'] != $config['captcha']['extra']
+			 || $_config['blotter'] != $config['blotter']
+			 || $_config['field_disable_name'] != $config['field_disable_name']
+			 || $_config['show_sages'] != $config['show_sages']) {
 				buildIndex();
 				$query = query(sprintf("SELECT `id` FROM ``posts_%s`` WHERE `thread` IS NULL", $b)) or error(db_error());
 				while ($post = $query->fetch(PDO::FETCH_ASSOC)) {
diff --git a/inc/config.php b/inc/config.php
index ebbe31a2..3adabcc9 100644
--- a/inc/config.php
+++ b/inc/config.php
@@ -272,6 +272,8 @@
 		'embed',
 		'recaptcha_challenge_field',
 		'recaptcha_response_field',
+		'captcha_cookie',
+		'captcha_text',
 		'spoiler',
 		'page',
 		'file_url',
@@ -300,6 +302,19 @@
 	$config['recaptcha_public'] = '6LcXTcUSAAAAAKBxyFWIt2SO8jwx4W7wcSMRoN3f';
 	$config['recaptcha_private'] = '6LcXTcUSAAAAAOGVbVdhmEM1_SyRF4xTKe8jbzf_';
 
+	$config['captcha'] = array();
+
+	// Enable custom captcha provider
+	$config['captcha']['enabled'] = false;
+
+	// Custom captcha provider path
+	$config['captcha']['provider_get']   = 'http://8chan.vichan.net/captcha/entrypoint.php';
+	$config['captcha']['provider_check'] = 'http://8chan.vichan.net/captcha/entrypoint.php';
+
+	// Custom captcha extra field (eg. charset)
+	$config['captcha']['extra'] = 'abcdefghijklmnopqrstuvwxyz';
+
+
 	/*
 	 * Custom filters detect certain posts and reject/ban accordingly. They are made up of a condition and an
 	 * action (for when ALL conditions are met). As every single post has to be put through each filter,
diff --git a/inc/instance-config.php b/inc/instance-config.php
index aa45f960..da57903c 100644
--- a/inc/instance-config.php
+++ b/inc/instance-config.php
@@ -91,6 +91,7 @@
 	$config['additional_javascript'][] = 'js/jquery.min.js';
 	$config['additional_javascript'][] = 'js/jquery.mixitup.min.js';
 	$config['additional_javascript'][] = 'js/catalog.js';
+	$config['additional_javascript'][] = 'js/captcha.js';
 	$config['additional_javascript'][] = 'js/jquery.tablesorter.min.js';
 	$config['additional_javascript'][] = 'js/options.js';
 	$config['additional_javascript'][] = 'js/style-select.js';
diff --git a/js/captcha.js b/js/captcha.js
new file mode 100644
index 00000000..1824214b
--- /dev/null
+++ b/js/captcha.js
@@ -0,0 +1,44 @@
+var tout;
+
+function redo_events(provider, extra) {
+  $('.captcha .captcha_text, textarea[id="body"]').off("focus").one("focus", function() { actually_load_captcha(provider, extra); });
+}
+
+function actually_load_captcha(provider, extra) {
+  $('.captcha .captcha_text, textarea[id="body"]').off("focus");
+
+  if (tout !== undefined) {
+    clearTimeout(tout);
+  }
+
+  $.getJSON(provider, {mode: 'get', extra: extra}, function(json) {
+    $(".captcha .captcha_cookie").val(json.cookie);
+    $(".captcha .captcha_html").html(json.captchahtml);
+
+    setTimeout(function() {
+      redo_events(provider, extra);      
+    }, json.expires_in * 1000);
+  });
+}
+
+function load_captcha(provider, extra) {
+  $(function() {
+    $(".captcha>td").html("<input class='captcha_text' type='text' name='captcha_text' size='25' maxlength='6' autocomplete='off'>"+
+			  "<input class='captcha_cookie' name='captcha_cookie' type='hidden'>"+
+			  "<div class='captcha_html'></div>");
+
+    $("#quick-reply .captcha .captcha_text").prop("placeholder", _("Verification"));
+
+    $(".captcha .captcha_html").on("click", function() { actually_load_captcha(provider, extra); });
+    $(document).on("ajax_after_post",       function() { actually_load_captcha(provider, extra); });
+    redo_events(provider, extra);
+
+    $(window).on("quick-reply", function() {
+      redo_events(provider, extra);
+      $("#quick-reply .captcha .captcha_html").html($("form:not(#quick-reply) .captcha .captcha_html").html());
+      $("#quick-reply .captcha .captcha_cookie").val($("form:not(#quick-reply) .captcha .captcha_cookie").html());
+      $("#quick-reply .captcha .captcha_html").on("click", function() { actually_load_captcha(provider, extra); });
+    });
+  });
+}
+
diff --git a/js/quick-reply.js b/js/quick-reply.js
index 07fe4aef..85503dd8 100644
--- a/js/quick-reply.js
+++ b/js/quick-reply.js
@@ -149,14 +149,14 @@
 						.removeAttr('size')
 						.attr('placeholder', $th.clone().children().remove().end().text());
 				}
-	
+
 				// Move anti-spam nonsense and remove <th>
 				$th.contents().filter(function() {
 					return this.nodeType == 3; // Node.TEXT_NODE
 				}).remove();
 				$th.contents().appendTo($dummyStuff);
 				$th.remove();
-	
+
 				if ($td.find('input[name="password"]').length) {
 					// Hide password field
 					$(this).hide();
@@ -280,7 +280,7 @@
 		
 		$postForm.find('textarea[name="body"]').removeAttr('id').removeAttr('cols').attr('placeholder', _('Comment'));
 	
-		$postForm.find('textarea:not([name="body"]),input[type="hidden"]').removeAttr('id').appendTo($dummyStuff);
+		$postForm.find('textarea:not([name="body"]),input[type="hidden"]:not(.captcha_cookie)').removeAttr('id').appendTo($dummyStuff);
 	
 		$postForm.find('br').remove();
 		$postForm.find('table').prepend('<tr><th colspan="2">\
diff --git a/post.php b/post.php
index 650b431b..bffc91c0 100644
--- a/post.php
+++ b/post.php
@@ -232,6 +232,21 @@ elseif (isset($_POST['post'])) {
 		}
 	}
 
+	// Same, but now with our custom captcha provider
+	if ($config['captcha']['enabled']) {
+		$resp = file_get_contents($config['captcha']['provider_check'] . "?" . http_build_query([
+			'mode' => 'check',
+			'text' => $_POST['captcha_text'],
+			'extra' => $config['captcha']['extra'],
+			'cookie' => $_POST['captcha_cookie']
+		]));
+
+		if ($resp !== '1') {
+                        error($config['error']['captcha'] .
+			'<script>if (actually_load_captcha !== undefined) actually_load_captcha("'.$config['captcha']['provider_get'].'", "'.$config['captcha']['extra'].'");</script>');
+		}
+	}
+
 	//if (!(($post['op'] && $_POST['post'] == $config['button_newtopic']) ||
 		//(!$post['op'] && $_POST['post'] == $config['button_reply'])))
 		//error($config['error']['bot']);
diff --git a/templates/mod/settings.html b/templates/mod/settings.html
index 487f82d8..74319aa4 100644
--- a/templates/mod/settings.html
+++ b/templates/mod/settings.html
@@ -44,6 +44,8 @@
 		<tr><th>{% trans %}Enable dice rolling{% endtrans %}</th><td><input type="checkbox" name="allow_roll" {% if config.allow_roll %}checked{% endif %}></td></tr>
 		<tr><th>{% trans %}Don't allow users to repost images{% endtrans %}</th><td><input type="checkbox" name="image_reject_repost" {% if config.image_reject_repost %}checked{% endif %}></td></tr>
 		<tr><th>{% trans %}Allow a poster to delete his own posts{% endtrans %}</th><td><input type="checkbox" name="allow_delete" {% if config.allow_delete %}checked{% endif %}></td></tr>
+		<tr><th>{% trans %}Enable captcha{% endtrans %}</th><td><input type="checkbox" name="captcha" {% if config.captcha.enabled %}checked{% endif %}></td></tr>
+		<tr><th>{% trans %}Captcha charset{% endtrans %}</th><td><input type="text" name="captcha_charset" value="{{ config.captcha.extra|e }}"></td></tr>
 		<tr><th>{% trans %}Language{% endtrans %}<br/><span class="unimportant">{% trans %}To contribute translations, register at <a href="https://www.transifex.com/projects/p/tinyboard-vichan-devel/">Transifex</a>{% endtrans %}</span></th><td>
 		<select name="locale">
 			<option value="en" {% if "en" == config.locale %}selected{% endif %}>en</option>
diff --git a/templates/post_form.html b/templates/post_form.html
index 34435e2a..93e6465f 100644
--- a/templates/post_form.html
+++ b/templates/post_form.html
@@ -80,6 +80,17 @@
 		</tr>
 		{% endif %}
 
+		{% if config.captcha.enabled %}
+		<tr class='captcha'>
+			<th>
+				{% trans %}Verification{% endtrans %}
+			</th>
+			<td>
+				<script>load_captcha("{{ config.captcha.provider_get }}", "{{ config.captcha.extra }}");</script>
+			</td>
+		</tr>
+		{% endif %}
+
 		{% if config.user_flag %}
 			<tr>
 				<th>{% trans %}Flag{% endtrans %}</th>