diff --git a/src/model.hpp b/src/model.hpp
index 3b773823d867983db54b5aa1ca86cac9513bfccb..3812a44bfffaa21397d12953c93fcd13bb3843d9 100644
--- a/src/model.hpp
+++ b/src/model.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <cstdlib>
 #include <vector>