diff --git a/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php b/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
index c7fd532d6ba83..5f0aa06dd0018 100644
--- a/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
+++ b/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
@@ -56,7 +56,7 @@ public function startQuery($sql, array $params = null, array $types = null)
                 }
 
                 // non utf-8 strings break json encoding
-                if (!preg_match('#[\p{L}\p{N} ]#u', $params[$index])) {
+                if (preg_match('#[^\p{L}\p{N} ]#u', $params[$index])) {
                     $params[$index] = self::BINARY_DATA_VALUE;
                     continue;
                 }