diff --git a/src/dynamic_array.h b/src/dynamic_array.h
index eaa96e7..ed575a9 100644
--- a/src/dynamic_array.h
+++ b/src/dynamic_array.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <stddef.h>
+
 #define DEFAULT_ARRAY_SIZE 10