diff --git a/include/lib/utils.h b/include/lib/utils.h
index b6ab26e..6748454 100644
--- a/include/lib/utils.h
+++ b/include/lib/utils.h
@@ -13,6 +13,7 @@
  */
 #if !(defined(__LINKER__) || defined(__ASSEMBLY__))
 
+#include <stddef.h>
 #include <stdint.h>
 
 typedef struct mem_region {