diff --git a/telephone_formatter.install b/telephone_formatter.install
index f44e696..9d67937 100644
--- a/telephone_formatter.install
+++ b/telephone_formatter.install
@@ -7,7 +7,7 @@ function telephone_formatter_requirements($phase) {
   $requirements = array();
   $t = get_t();
 
-  if (!class_exists('\libphonenumber\PhoneNumberUtil')) {
+  if (!module_exists('composer_manager') && !class_exists('\libphonenumber\PhoneNumberUtil')) {
     $requirements['telephone_formatter'] = array(
       'title' => $t('libphonenumber library'),
       'description' => $t('Telephone Formatter requires the <a href="@library_url">libphonenumber</a> library to be installed and autoloaded with composer (e.g. using the <a href="@composer_manager_url">composer_manager</a> module).', array(