diff --git a/api/v1/database/mastodon/accounts/search/mod.php b/api/v1/database/mastodon/accounts/search/mod.php
index 495168a..80f9824 100644
--- a/api/v1/database/mastodon/accounts/search/mod.php
+++ b/api/v1/database/mastodon/accounts/search/mod.php
@@ -59,20 +59,36 @@ $sql_all = '
 ';
 
 $instances = null;
+$ninstances = null;
 if (isset($_GET['instances'])) {
 	$instances = [];
+	$ninstances = [];
 	foreach (explode(',',$_GET['instances']) as $instance) {
 		$instance = trim($instance);
-		if (valid_domain_name($instance))
-			$instances []= "'".$instance."'";
+		$not_bool = $instance[0] === '!';
+		if ($not_bool)
+			$instance = substr($instance, 1);
+		if (valid_domain_name($instance)) {
+			if ($not_bool)
+				$ninstances []= "'".$instance."'";
+			else $instances []= "'".$instance."'";
+		}
 	}
 	if (count($instances) > 0)
 		$instances = implode(',', $instances);
 	else $instances = null;
+	if (count($ninstances) > 0)
+		$ninstances = implode(',', $ninstances);
+	else $ninstances = null;
 }
+$_ = '';
 if ($instances !== null)
-	$sql_all = str_replace('{instanceFilter}', "a.domain IN ($instances) AND", $sql_all);
-else $sql_all = str_replace('{instanceFilter}', '', $sql_all);
+	$_ .= "a.domain IN ($instances) AND ";
+if ($ninstances !== null)
+	$_ .= "NOT a.domain IN ($ninstances) AND ";
+$_ = trim($_);
+$sql_all = str_replace('{instanceFilter}', $_, $sql_all);
+unset($_);
 
 $user_filter = 'local';
 if (isset($_GET['user_filter'])) {