diff --git a/lib/system/zephyr/sys.h b/lib/system/zephyr/sys.h
index 9133e105..781c8871 100644
--- a/lib/system/zephyr/sys.h
+++ b/lib/system/zephyr/sys.h
@@ -17,6 +17,7 @@
 #define __METAL_ZEPHYR_SYS__H__
 
 #include <stdlib.h>
+#include <zephyr/kernel.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -39,6 +40,11 @@ struct metal_state {
 	struct metal_common_state common;
 };
 
+static inline void metal_wait_usec(void)
+{
+	k_busy_wait(1);
+}
+
 #ifdef __cplusplus
 }
 #endif