diff --git a/arch/m68knommu/platform/5206e/Makefile b/arch/m68knommu/platform/5206e/Makefile
index c7bb0ce..a439d9a 100644
--- a/arch/m68knommu/platform/5206e/Makefile
+++ b/arch/m68knommu/platform/5206e/Makefile
@@ -12,9 +12,7 @@
 # EXTRA_AFLAGS += -DTRAP_DBG_INTERRUPT
 #
 
-ifdef CONFIG_FULLDEBUG
-EXTRA_AFLAGS += -DDEBUGGER_COMPATIBLE_CACHE=1
-endif
+asflags-$(CONFIG_FULLDEBUG) := -DDEBUGGER_COMPATIBLE_CACHE=1
 
 obj-y := config.o