1 files changed, 2 insertions, 6 deletions
diff --git a/Makefile b/Makefile
index 82993a4..e278c52 100644
--- a/Makefile
+++ b/Makefile
@@ -12,15 +12,11 @@ ifeq ($(shell which qemu-system-$(shell uname -m | sed 's/i686/i386/') 2>&1 > /d
 endif
 ifeq ($(shell which virtualbox 2>&1 > /dev/null && echo $$?), 0)
     AVAILABLE_BUILDERS += virtualbox-iso
-    ifndef DEFAULT_BUILDER
-        DEFAULT_BUILDER := virtualbox-iso
-    endif
+    DEFAULT_BUILDER    ?= virtualbox-iso
 endif
 ifeq ($(shell which vmplayer 2>&1 > /dev/null && echo $$?), 0)
     AVAILABLE_BUILDERS += vmware-iso
-    ifndef DEFAULT_BUILDER
-        DEFAULT_BUILDER := vmware-iso
-    endif
+    DEFAULT_BUILDER    ?= vmware-iso
 endif
 ifndef BUILDER
     $(info # BUILDER not set, using default builder: $(DEFAULT_BUILDER))