diff --git a/boot/zephyr/prj.conf b/boot/zephyr/prj.conf
index 8d3cdb819..a6da04933 100644
--- a/boot/zephyr/prj.conf
+++ b/boot/zephyr/prj.conf
@@ -1,4 +1,3 @@
-CONFIG_DEBUG=y
 CONFIG_PM=n
 
 CONFIG_MAIN_STACK_SIZE=10240
diff --git a/docs/release-notes.d/zephyr-debug.md b/docs/release-notes.d/zephyr-debug.md
new file mode 100644
index 000000000..71a09f75e
--- /dev/null
+++ b/docs/release-notes.d/zephyr-debug.md
@@ -0,0 +1,2 @@
+- Zephyr no longer builds in optimize for debug mode, this saves a
+  significant amount of flash space.