diff --git a/lib/Alchemy/Phrasea/TaskManager/Log/AbstractLogFile.php b/lib/Alchemy/Phrasea/TaskManager/Log/AbstractLogFile.php
index bdc03bed1b..10608d3ba7 100644
--- a/lib/Alchemy/Phrasea/TaskManager/Log/AbstractLogFile.php
+++ b/lib/Alchemy/Phrasea/TaskManager/Log/AbstractLogFile.php
@@ -66,7 +66,7 @@ abstract class AbstractLogFile implements LogFileInterface
      */
     public function clear($version = '')
     {
-        file_put_contents($this->getPath($version), sprintf("File cleared %s\n", date('r')));
+        file_put_contents($this->getPath($version), sprintf("[%s] File cleared\n", date(\DateTime::ATOM)));
     }
 
     /**
diff --git a/lib/Alchemy/Phrasea/TaskManager/Log/LogFileInterface.php b/lib/Alchemy/Phrasea/TaskManager/Log/LogFileInterface.php
index be33b80393..15628b6d3a 100644
--- a/lib/Alchemy/Phrasea/TaskManager/Log/LogFileInterface.php
+++ b/lib/Alchemy/Phrasea/TaskManager/Log/LogFileInterface.php
@@ -28,7 +28,7 @@ interface LogFileInterface
      * @param string $version
      * @return string
      */
-    public function getPath($version);
+    public function getPath($version = '');
 
     /**
      * Returns the content of a logfile.
@@ -36,7 +36,7 @@ interface LogFileInterface
      * @param string $version
      * @return string
      */
-    public function getContent($version);
+    public function getContent($version = '');
 
     /**
      * Streams the content of a logfile.
@@ -46,14 +46,14 @@ interface LogFileInterface
      * @param string $version
      * @return Closure
      */
-    public function getContentStream($version);
+    public function getContentStream($version = '');
 
     /**
      * Clears the content of a logfile.
      *
      * @param string $version
      */
-    public function clear($version);
+    public function clear($version = '');
 
     /**
      * Returns true if the logfile exists
diff --git a/tests/Alchemy/Tests/Phrasea/TaskManager/Log/LogFileTestCase.php b/tests/Alchemy/Tests/Phrasea/TaskManager/Log/LogFileTestCase.php
index 480eda6864..120f88945a 100644
--- a/tests/Alchemy/Tests/Phrasea/TaskManager/Log/LogFileTestCase.php
+++ b/tests/Alchemy/Tests/Phrasea/TaskManager/Log/LogFileTestCase.php
@@ -60,7 +60,9 @@ abstract class LogFileTestCase extends \PhraseanetTestCase
         $log = $this->getLogFile($this->root);
         file_put_contents($log->getPath(), 'hello world');
         $log->clear();
-        $this->assertSame('', $log->getContent());
+        $matches = [];
+        $this->assertEquals(1, preg_match('/^\[(.*)\] File cleared/', $log->getContent(), $matches));
+        $this->assertDateAtom($matches[1]);
     }
 
     /**