diff --git a/Jobs/ZUGFeRD/ImportZUGFeRDFiles.vb b/Jobs/ZUGFeRD/ImportZUGFeRDFiles.vb
index 00fd4714..e14b4ec9 100644
--- a/Jobs/ZUGFeRD/ImportZUGFeRDFiles.vb
+++ b/Jobs/ZUGFeRD/ImportZUGFeRDFiles.vb
@@ -222,7 +222,7 @@ Public Class ImportZUGFeRDFiles
                                     oEmailAttachmentFiles.Add(oFile)
 
                                     ' Checking filesize for attachment files
-                                    If Check_FileSize(oFile, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
+                                    If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
                                         _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
                                         Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
                                     End If
@@ -233,7 +233,7 @@ Public Class ImportZUGFeRDFiles
                                 _logger.Info("Start processing file {0}", oFile.Name)
 
                                 ' Checking filesize for pdf files
-                                If Check_FileSize(oFile, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
+                                If _filesystem.TestFileSizeIsLessThanMaxFileSize(oFile.FullName, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
                                     _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
                                     Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
                                 End If
@@ -844,30 +844,4 @@ Public Class ImportZUGFeRDFiles
 
         Return oMD5CheckSum
     End Function
-
-    ''' <summary>
-    ''' Checks the size of the supplied file.
-    ''' </summary>
-    ''' <param name="pFileInfo"></param>
-    ''' <param name="pMaxFileSizeInMegaBytes"></param>
-    ''' <returns></returns>
-    Private Function Check_FileSize(pFileInfo As FileInfo, pMaxFileSizeInMegaBytes As Integer) As Boolean
-        _logger.Info("Checking Filesize of {0}", pFileInfo.Name)
-        _logger.Debug("Filesize threshold is {0} MB.", pMaxFileSizeInMegaBytes)
-
-        If pMaxFileSizeInMegaBytes <= 0 Then
-            _logger.Debug("Filesize is not configured. Skipping check.")
-            Return True
-        End If
-
-        Dim oMaxSize = pMaxFileSizeInMegaBytes * 1024 * 1024
-
-        If oMaxSize > 0 And pFileInfo.Length > oMaxSize Then
-            _logger.Debug("Filesize is bigger than threshold. Rejecting.")
-            Return False
-        Else
-            _logger.Debug("Filesize is smaller than threshold. All fine.")
-            Return True
-        End If
-    End Function
 End Class