diff --git a/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php b/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
index 3d103e215c..617dd5c3fa 100644
--- a/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
+++ b/src/Symfony/Bridge/Doctrine/Logger/DbalLogger.php
@@ -56,15 +56,15 @@ class DbalLogger implements SQLLogger
                 }
 
                 // non utf-8 strings break json encoding
-                if (!preg_match('#[\p{L}\p{N} ]#u', $params[$index])) {
+                if (!preg_match('//u', $params[$index])) {
                     $params[$index] = self::BINARY_DATA_VALUE;
                     continue;
                 }
 
                 // detect if the too long string must be shorten
-                if (function_exists('mb_detect_encoding') && false !== $encoding = mb_detect_encoding($params[$index])) {
-                    if (self::MAX_STRING_LENGTH < mb_strlen($params[$index], $encoding)) {
-                        $params[$index] = mb_substr($params[$index], 0, self::MAX_STRING_LENGTH - 6, $encoding).' [...]';
+                if (function_exists('mb_strlen')) {
+                    if (self::MAX_STRING_LENGTH < mb_strlen($params[$index], 'UTF-8')) {
+                        $params[$index] = mb_substr($params[$index], 0, self::MAX_STRING_LENGTH - 6, 'UTF-8').' [...]';
                         continue;
                     }
                 } else {
diff --git a/src/Symfony/Bridge/Doctrine/Tests/Logger/DbalLoggerTest.php b/src/Symfony/Bridge/Doctrine/Tests/Logger/DbalLoggerTest.php
index 741c894e33..0c39008d49 100644
--- a/src/Symfony/Bridge/Doctrine/Tests/Logger/DbalLoggerTest.php
+++ b/src/Symfony/Bridge/Doctrine/Tests/Logger/DbalLoggerTest.php
@@ -43,7 +43,10 @@ class DbalLoggerTest extends \PHPUnit_Framework_TestCase
         return array(
             array('SQL', null, array()),
             array('SQL', array(), array()),
-            array('SQL', array('foo' => 'bar'), array('foo' => 'bar'))
+            array('SQL', array('foo' => 'bar'), array('foo' => 'bar')),
+            array('SQL', array('foo' => "\x7F\xFF"), array('foo' => DbalLogger::BINARY_DATA_VALUE)),
+            array('SQL', array('foo' => "bar\x7F\xFF"), array('foo' => DbalLogger::BINARY_DATA_VALUE)),
+            array('SQL', array('foo' => ''), array('foo' => '')),
         );
     }