diff --git a/htdocs/langs/en_US/admin.lang b/htdocs/langs/en_US/admin.lang
index 8f9c4aa302f..2cd9d55aefb 100644
--- a/htdocs/langs/en_US/admin.lang
+++ b/htdocs/langs/en_US/admin.lang
@@ -1932,7 +1932,7 @@ BackupDumpWizard=Wizard to build the database dump file
 BackupZipWizard=Wizard to build the archive of documents directory
 SomethingMakeInstallFromWebNotPossible=Installation of external module is not possible from the web interface for the following reason:
 SomethingMakeInstallFromWebNotPossible2=For this reason, process to upgrade described here is a manual process only a privileged user may perform.
-InstallModuleFromWebHasBeenDisabledContactUs=Install of external modules from the application is currently locked. Please contact us if you need us to enable this feature.
+InstallModuleFromWebHasBeenDisabledContactUs=Install or development of external modules from the application is currently locked for security purpose. Please contact us if you need to enable this feature.
 InstallModuleFromWebHasBeenDisabledByFile=Install of external module from application has been disabled by your administrator. You must ask him to remove the file <strong>%s</strong> to allow this feature.
 ConfFileMustContainCustom=Installing or building an external module from application need to save the module files into directory <strong>%s</strong>. To have this directory processed by Dolibarr, you must setup your <strong>conf/conf.php</strong> to add the 2 directive lines:<br><strong>$dolibarr_main_url_root_alt='/custom';</strong><br><strong>$dolibarr_main_document_root_alt='%s/custom';</strong>
 HighlightLinesOnMouseHover=Highlight table lines when mouse move passes over
diff --git a/htdocs/modulebuilder/index.php b/htdocs/modulebuilder/index.php
index 29959822af1..538b1cac290 100644
--- a/htdocs/modulebuilder/index.php
+++ b/htdocs/modulebuilder/index.php
@@ -1974,6 +1974,28 @@ if ($message) {
 $infomodulesfound = '<div style="padding: 12px 9px 12px">'.$form->textwithpicto('', $langs->trans("ModuleBuilderDesc3", count($listofmodules)).'<br><br>'.$langs->trans("ModuleBuilderDesc4", $FILEFLAG).'<br>'.$textforlistofdirs).'</div>';
 
 
+
+$dolibarrdataroot = preg_replace('/([\\/]+)$/i', '', DOL_DATA_ROOT);
+$allowonlineinstall = true;
+if (dol_is_file($dolibarrdataroot.'/installmodules.lock')) {
+	$allowonlineinstall = false;
+}
+if (empty($allowonlineinstall)) {
+	if (getDolGlobalString('MAIN_MESSAGE_INSTALL_MODULES_DISABLED_CONTACT_US')) {
+		// Show clean message
+		$message = info_admin($langs->trans('InstallModuleFromWebHasBeenDisabledContactUs'));
+	} else {
+		// Show technical message
+		$message = info_admin($langs->trans("InstallModuleFromWebHasBeenDisabledByFile", $dolibarrdataroot.'/installmodules.lock'), 0, 0, 1, 'warning');
+	}
+
+	print $message;
+
+	llxFooter();
+	exit(0);
+}
+
+
 // Load module descriptor
 $error = 0;
 $moduleobj = null;