diff --git a/makefile b/makefile
index da8567d..4c31db2 100644
--- a/makefile
+++ b/makefile
@@ -53,6 +53,11 @@
 ifeq ($(EMMC_BOOT),1)
   CFLAGS += -D_EMMC_BOOT=1
 endif
+
+ifeq ($(SIGNED_KERNEL),1)
+  CFLAGS += -D_SIGNED_KERNEL=1
+endif
+
 # When the host arch is ARM, ensure stack protection code is not emitted since
 # it's not supported by the bootloader's libc
 ifneq ($(shell uname -m | grep "arm.*"),)