diff --git a/src/xrt/auxiliary/util/u_misc.h b/src/xrt/auxiliary/util/u_misc.h
index b854a8a3a63fb2d98884ce6dcff19ff0f2abfb96..709018e644fac4a270a9f886a3ec0d637d0d5958 100644
--- a/src/xrt/auxiliary/util/u_misc.h
+++ b/src/xrt/auxiliary/util/u_misc.h
@@ -8,6 +8,8 @@
 
 #pragma once
 
+#include <stdlib.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif