diff --git a/htdocs/admin/tools/export_files.php b/htdocs/admin/tools/export_files.php
index 6e0b0508a07b3..5ec1d5d56f7c8 100644
--- a/htdocs/admin/tools/export_files.php
+++ b/htdocs/admin/tools/export_files.php
@@ -113,7 +113,8 @@
 if ($compression == 'zip')
 {
 	$file .= '.zip';
-	$ret = dol_compress_dir(DOL_DATA_ROOT, $outputdir."/".$file, $compression, '/(\.back|\.old|\.log|[\\\/]temp[\\\/]|documents[\\\/]admin[\\\/]documents[\\\/])/i');
+	$excludefiles = '/(\.back|\.old|\.log|[\/\\\]temp[\/\\\]|documents[\/\\\]admin[\/\\\]documents[\/\\\])/i';
+	$ret = dol_compress_dir(DOL_DATA_ROOT, $outputdir."/".$file, $compression, $excludefiles);
 	if ($ret < 0)
 	{
 		if ($ret == -2) {
diff --git a/test/phpunit/FilesLibTest.php b/test/phpunit/FilesLibTest.php
index d80abac42fea7..ef84b8db752d0 100644
--- a/test/phpunit/FilesLibTest.php
+++ b/test/phpunit/FilesLibTest.php
@@ -425,6 +425,13 @@ public function testDolCompressUnCompress()
         $result=dol_uncompress($fileout, $dirout);
         print __METHOD__." result=".join(',', $result)."\n";
         $this->assertEquals(0, count($result), "Pb with dol_uncompress_file of file ".$fileout);
+
+        $excludefiles = '/(\.back|\.old|\.log|documents[\/\\\]admin[\/\\\]documents[\/\\\])/i';
+        if (preg_match($excludefiles, 'a/temp/b')) { echo '----- Regex OK -----'."\n"; }
+        $result=dol_compress_dir($dirout, $conf->admin->dir_temp.'/testdir.zip', 'zip', $excludefiles);
+        print __METHOD__." result=".$result."\n";
+        print join(', ', $conf->logbuffer);
+        $this->assertGreaterThanOrEqual(1, $result, "Pb with dol_compress_dir of ".$dirout." into ".$conf->admin->dir_temp.'/testdir.zip');
     }
 
     /**