diff --git a/htdocs/core/class/translate.class.php b/htdocs/core/class/translate.class.php
index a9fe00d0ebf..4955123056f 100644
--- a/htdocs/core/class/translate.class.php
+++ b/htdocs/core/class/translate.class.php
@@ -246,7 +246,7 @@ class Translate {
 								$tab=explode('=',$line,2);
 								$key=trim($tab[0]);
 								//print "Domain=$domain, found a string for $tab[0] with value $tab[1]<br>";
-								if (empty($this->tab_translate[$key]) && isset($tab[1]))    // If data was already found, we must not enter here, even if MAIN_FORCELANGDIR is set (MAIN_FORCELANGDIR is to replace lang dir, not to overwrite)
+								if ((! empty($conf->global->MAIN_USE_CUSTOM_TRANSLATION) || empty($this->tab_translate[$key])) && isset($tab[1]))    // If data was already found, we must not enter here, even if MAIN_FORCELANGDIR is set (MAIN_FORCELANGDIR is to replace lang dir, not to overwrite)
 								{
 									$value=trim(preg_replace('/\\n/',"\n",$tab[1]));
 
@@ -288,7 +288,7 @@ class Translate {
 							$size=dol_setcache($usecachekey,$tabtranslatedomain);
 						}
 
-						if (empty($conf->global->MAIN_FORCELANGDIR)) break;		// Break loop on each root dir. If a module has forced dir, we do not stop loop.
+						if (empty($conf->global->MAIN_FORCELANGDIR) && empty($conf->global->MAIN_USE_CUSTOM_TRANSLATION)) break;		// Break loop on each root dir. If a module has forced dir, we do not stop loop.
 					}
 				}
 			}