diff --git a/inc/config.php b/inc/config.php
index 746fcad6..da37ab93 100644
--- a/inc/config.php
+++ b/inc/config.php
@@ -236,6 +236,19 @@
     // To prevent bump atacks; returns the thread to last position after the last post is deleted.
     $config['anti_bump_flood'] = false;
 
+    // IPHub API key for checking for bad proxies (leave blank to not use IPHub) https://iphub.info/api
+    $config['iphub_key'] = "";
+
+    // If you find that a lot of spammers are comming from a specific ISP, or ASN,
+    // you can put the ISP in iphub_banned_isps and/or the ASN in iphub_banned_asns
+    // USE THIS WITH CAUTION, IT MAY PREVENT NON-SPAMMERS FROM POSTING
+    $config['iphub_banned_isps'] = [];
+    $config['iphub_banned_asns'] = [];
+
+    // IPs in this array won't be checked by IPHub
+    // This can be used if legitimate posters are getting blocked by IPHub
+    $config['iphub_whitelisted_ips'] = [];
+
     /*
      * Introduction to Tinyboard's spam filter:
      *
@@ -1198,6 +1211,7 @@
 
     // Error messages
     $config['error']['bot']         = _('You look like a bot.');
+    $config['error']['proxy']		= _('You seem to be using an unathorized proxy.');
     $config['error']['referer']     = _('Your browser sent an invalid or no HTTP referer.');
     $config['error']['toolong']     = _('The %s field was too long.');
     $config['error']['toolong_body']    = _('The body was too long.');
diff --git a/inc/functions.php b/inc/functions.php
index 644cefbe..6df52894 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -1823,6 +1823,47 @@ function buildJavascript() {
 	file_write($config['file_script'], $script);
 }
 
+function checkIPAPI() {
+	global $config;
+
+	// query IPHub's database with the poster's IP
+	if (isset($config['iphub_key']) && $config['iphub_key'] !== "") {
+		if (isset($config['iphub_whitelisted_ips']) && array_search($_SERVER['REMOTE_ADDR'], $config['iphub_whitelisted_ips']) !== false) {
+			// IP is whitelisted, don't bother querying
+			error("return true;");
+		}
+
+		$ch = curl_init();
+		curl_setopt($ch, CURLOPT_URL, "http://v2.api.iphub.info/ip/" . $_SERVER['REMOTE_ADDR']);
+		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
+		curl_setopt($ch, CURLOPT_HTTPHEADER, array("X-Key: " . $config['iphub_key']));
+		$reply = curl_exec($ch);
+		if ($reply == "") {
+			return false;
+		}
+
+		$json = json_decode($reply);
+		if (isset($json->error)) {
+			$logdata = array();
+			$logdata['time'] = date(DATE_ATOM);
+			$logdata['action'] = 'iphub_query';
+			$logdata['msg'] = $json->error;
+
+			$logline = json_encode($logdata);
+			error_log($logline);
+			return false;
+		}
+
+		if ($json->block == 1
+		  || (isset($config['iphub_banned_asns']) && array_search($json->asn, $config['iphub_banned_asns']) !== false)
+		  || (isset($config['iphub_banned_isps']) && array_search($json->isp, $config['iphub_banned_isps']) !== false)) {
+			error($config['error']['proxy']);
+			return true;
+		}
+	}
+	return false;
+}
+
 function checkDNSBL() {
 	global $config;