diff --git a/ports/zephyr/prj.conf b/ports/zephyr/prj.conf
index b6559e4f7..90211e365 100644
--- a/ports/zephyr/prj.conf
+++ b/ports/zephyr/prj.conf
@@ -1,4 +1,5 @@
 CONFIG_BUILD_OUTPUT_BIN=y
+CONFIG_BUILD_OUTPUT_HEX=y
 CONFIG_REBOOT=y
 
 CONFIG_STDOUT_CONSOLE=y