diff --git a/dev/translation/strip_language_file.php b/dev/translation/strip_language_file.php
index ce28ca5de63..f2263b1d18b 100755
--- a/dev/translation/strip_language_file.php
+++ b/dev/translation/strip_language_file.php
@@ -250,11 +250,11 @@ foreach($filesToProcess as $fileToProcess)
 	{
 		if ( ! $oh = fopen($output, 'w') )
 		{
-			print "ERROR in writing to file $output\n";
+			print "ERROR in writing to file ".$output."\n";
 			exit;
 		}
 
-		print "Read Primary File $lPrimaryFile and write ".$output.":\n";
+		print "Read Primary File ".$lPrimaryFile." and write ".$output.":\n";
 
 		fwrite($oh, "# Dolibarr language file - Source file is en_US - ".(preg_replace('/\.lang$/', '', $fileToProcess))."\n");
 
diff --git a/test/phpunit/LangTest.php b/test/phpunit/LangTest.php
index f4a14373ebe..7802bc57659 100644
--- a/test/phpunit/LangTest.php
+++ b/test/phpunit/LangTest.php
@@ -181,6 +181,20 @@ class LangTest extends PHPUnit\Framework\TestCase
 			$this->assertRegExp('/^[dMy\/\-\.]+$/', $result, 'FormatDateShortJavaInput KO for lang code '.$code);
 
 			unset($tmplangs);
+
+			$filesarray2 = scandir(DOL_DOCUMENT_ROOT.'/langs/'.$code);
+			foreach($filesarray2 as $key => $file) {
+				if (! preg_match('/\.lang$/', $file)) {
+					continue;
+				}
+
+				print 'Check lang file '.$file."\n";
+				$filecontent=file_get_contents(DOL_DOCUMENT_ROOT.'/langs/'.$code.'/'.$file);
+
+				$result=strpos($filecontent, '％');
+				print __METHOD__." Result for checking we don't have bad percent char = ".$result."\n";
+				$this->assertTrue($result===false, 'Found a bad percent char ％ instead of % into file '.$code.'/'.$file);
+			}
 		}
 
         return;