diff --git a/htdocs/langs/en_US/main.lang b/htdocs/langs/en_US/main.lang
index 1859c9814ff..649dd3fa31f 100644
--- a/htdocs/langs/en_US/main.lang
+++ b/htdocs/langs/en_US/main.lang
@@ -1,9 +1,15 @@
 # Dolibarr language file - Source file is en_US - main
 DIRECTION=ltr
+# Default for FONTFORPDF=helvetica
 # Note for Chinese:
-# msungstdlight or cid0ct are for traditional Chinese (traditional does not render with Ubuntu pdf reader)
-# stsongstdlight or cid0cs are for simplified Chinese
+# msungstdlight or cid0ct are for traditional Chinese zh_TW (traditional does not render with Ubuntu pdf reader)
+# stsongstdlight or cid0cs are for simplified Chinese zh_CN
 # To read Chinese pdf with Linux: sudo apt-get install poppler-data
+# cid0jp is for Japanish
+# cid0kr is for Korean
+# DejaVuSans is for some Eastern languages, some Asian languages and some Arabic languages
+# freemono is for ru_RU or uk_UA, uz_UZ
+# freeserif is for Tamil
 FONTFORPDF=helvetica
 FONTSIZEFORPDF=10
 SeparatorDecimal=.
diff --git a/htdocs/langs/ru_UA/main.lang b/htdocs/langs/ru_UA/main.lang
index 2e691473326..0884e5426e0 100644
--- a/htdocs/langs/ru_UA/main.lang
+++ b/htdocs/langs/ru_UA/main.lang
@@ -1,6 +1,6 @@
 # Dolibarr language file - Source file is en_US - main
 DIRECTION=ltr
-FONTFORPDF=helvetica
+FONTFORPDF=freemono
 FONTSIZEFORPDF=10
 SeparatorDecimal=.
 SeparatorThousand=,
diff --git a/test/phpunit/LangTest.php b/test/phpunit/LangTest.php
index d3f91093124..c9c332b311e 100644
--- a/test/phpunit/LangTest.php
+++ b/test/phpunit/LangTest.php
@@ -186,7 +186,7 @@ class LangTest extends PHPUnit\Framework\TestCase
 
 			$result=$tmplangs->transnoentitiesnoconv("FONTFORPDF");
 			print __METHOD__." FONTFORPDF=".$result."\n";
-			$this->assertTrue(in_array($result, array('msungstdlight', 'stsongstdlight', 'helvetica', 'DejaVuSans', 'cid0jp', 'cid0kr', 'freemono')), 'Error bad value '.$result.' for FONTFORPDF in main.lang file '.$code);
+			$this->assertTrue(in_array($result, array('msungstdlight', 'stsongstdlight', 'helvetica', 'DejaVuSans', 'cid0jp', 'cid0kr', 'freemono', 'freeserif')), 'Error bad value '.$result.' for FONTFORPDF in main.lang file '.$code);
 
 			$result=$tmplangs->transnoentitiesnoconv("DIRECTION");
 			print __METHOD__." DIRECTION=".$result."\n";