diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 66de2ad..c69654c 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -6,6 +6,7 @@
 
 choice
 	prompt "Target select"
+	optional
 
 config TARGET_ATNGW100
 	bool "Support atngw100"