diff --git a/Kbuild b/Kbuild
index 8b88845..3bfa260 100644
--- a/Kbuild
+++ b/Kbuild
@@ -1292,6 +1292,7 @@
 ifeq ($(CONFIG_HELIUMPLUS),y)
 CDEFINES += -DHELIUMPLUS_PADDR64
 CDEFINES += -DHELIUMPLUS
+CDEFINES += -DAR900B
 ifeq ($(CONFIG_64BIT_PADDR),y)
 CDEFINES += -DHTT_PADDR64
 endif