diff --git a/src/Monolog/Logger.php b/src/Monolog/Logger.php
index 6d48c135..517e9996 100644
--- a/src/Monolog/Logger.php
+++ b/src/Monolog/Logger.php
@@ -415,6 +415,10 @@ class Logger implements LoggerInterface, ResettableInterface
             throw new InvalidArgumentException('Level "'.$level.'" is not defined, use one of: '.implode(', ', array_keys(static::$levels)));
         }
 
+        if (!is_int($level)) {
+            throw new InvalidArgumentException('Level "'.var_export($level, true).'" is not defined, use one of: '.implode(', ', array_keys(static::$levels)));
+        }
+
         return $level;
     }
 
diff --git a/tests/Monolog/Handler/SyslogUdpHandlerTest.php b/tests/Monolog/Handler/SyslogUdpHandlerTest.php
index 4c715920..4ef2390c 100644
--- a/tests/Monolog/Handler/SyslogUdpHandlerTest.php
+++ b/tests/Monolog/Handler/SyslogUdpHandlerTest.php
@@ -83,7 +83,7 @@ class SyslogUdpHandlerTest extends TestCase
         $host = gethostname();
 
         $handler = $this->getMockBuilder('\Monolog\Handler\SyslogUdpHandler')
-            ->setConstructorArgs(array("127.0.0.1", 514, "authpriv", null, null, "php", \Monolog\Handler\SyslogUdpHandler::RFC3164))
+            ->setConstructorArgs(array("127.0.0.1", 514, "authpriv", 'debug', true, "php", \Monolog\Handler\SyslogUdpHandler::RFC3164))
             ->setMethods(array('getDateTime'))
             ->getMock();
 
@@ -92,7 +92,10 @@ class SyslogUdpHandlerTest extends TestCase
 
         $handler->setFormatter(new \Monolog\Formatter\ChromePHPFormatter());
 
-        $socket = $this->getMock('\Monolog\Handler\SyslogUdp\UdpSocket', array('write'), array('lol', 'lol'));
+        $socket = $this->getMockBuilder('\Monolog\Handler\SyslogUdp\UdpSocket')
+            ->setConstructorArgs(array('lol', 999))
+            ->setMethods(array('write'))
+            ->getMock();
         $socket->expects($this->at(0))
             ->method('write')
             ->with("lol", "<".(LOG_AUTHPRIV + LOG_WARNING).">$time $host php[$pid]: ");