diff --git a/htdocs/install/check.php b/htdocs/install/check.php
index 14448841217..d3c5cba1290 100644
--- a/htdocs/install/check.php
+++ b/htdocs/install/check.php
@@ -149,11 +149,19 @@ if (!function_exists("easter_date")) {
 if (!function_exists("utf8_encode")) {
 	$langs->load("errors");
 	print '<img src="../theme/eldy/img/warning.png" alt="Error" class="valignmiddle"> '.$langs->trans("ErrorPHPDoesNotSupportUTF8")."<br>\n";
-	// $checksok = 0;		// If ko, just warning. So check must still be 1 (otherwise no way to install)
+	// $checksok = 0; // If ko, just warning. So check must still be 1 (otherwise no way to install)
 } else {
 	print '<img src="../theme/eldy/img/tick.png" alt="Ok" class="valignmiddle"> '.$langs->trans("PHPSupport", "UTF8")."<br>\n";
 }
 
+// Check for mbstring extension
+if (!extension_loaded("mbstring")) {
+	$langs->load("errors");
+	print '<img src="../theme/eldy/img/warning.png" alt="Error" class="valignmiddle"> '.$langs->trans("ErrorPHPDoesNotSupportMbstring")."<br>\n";
+	// $checksok = 0; // If ko, just warning. So check must still be 1 (otherwise no way to install)
+} else {
+	print '<img src="../theme/eldy/img/tick.png" alt="Ok" class="valignmiddle"> '.$langs->trans("PHPSupport", "mbstring")."<br>\n";
+}
 
 // Check if intl methods are supported
 if (empty($_SERVER["SERVER_ADMIN"]) || $_SERVER["SERVER_ADMIN"] != 'doliwamp@localhost') {