diff --git a/arch.mk b/arch.mk
index 7e942b41..88b50819 100644
--- a/arch.mk
+++ b/arch.mk
@@ -23,4 +23,4 @@ else
 $(error Could not determine operating system of $(MACHINE))
 endif
 
-ARCH_NAME := $(ARCH_OS)_$(ARCH_CPU)
+ARCH_NAME := $(ARCH_OS)-$(ARCH_CPU)