diff --git a/include/pam_authenticate.hpp b/include/pam_authenticate.hpp
index d0ca1b0..5b4b454 100644
--- a/include/pam_authenticate.hpp
+++ b/include/pam_authenticate.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <security/pam_appl.h>
+#include <memory>
 #include <cstring>
 
 // function used to get user input