Index: defaults/amd64/Makefile.config
===================================================================
--- defaults/amd64/Makefile.config	(revision 1d40c93d3c9528f07c921998be888691e0ac590c)
+++ defaults/amd64/Makefile.config	(revision b4a9f5dda20b7206e43da8d1fe37aa4eee1ff024)
@@ -73,2 +73,5 @@
 # GRUB boot loader architecture
 GRUB_ARCH = pc
+
+# Optimization level
+OPTIMIZATION = 3