1 files changed, 11 insertions, 9 deletions
diff --git a/Makefile b/Makefile
index 6f626cc..a8adeae 100644
--- a/Makefile
+++ b/Makefile
@@ -6,16 +6,18 @@ PACKER = packer
 ANSIBLE_DIR = ansible-roles
 
 # check which hypervisors are available
-ifeq ($(shell which qemu-system-$(shell uname -m | sed 's/i686/i386/') 2>&1 > /dev/null && echo $$?), 0)
-    AVAILABLE_BUILDERS += qemu
+ifndef BUILDER
+    ifeq ($(shell which qemu-system-$(shell uname -m | sed 's/i686/i386/') 2>&1 > /dev/null && echo $$?), 0)
+        AVAILABLE_BUILDERS += qemu
+    endif
+    ifeq ($(shell which virtualbox 2>&1 > /dev/null && echo $$?), 0)
+        AVAILABLE_BUILDERS += virtualbox-iso
+    endif
+    ifeq ($(shell which vmplayer 2>&1 > /dev/null && echo $$?), 0)
+        AVAILABLE_BUILDERS += vmware-iso
+    endif
+    BUILDER := $(firstword $(AVAILABLE_BUILDERS))
 endif
-ifeq ($(shell which virtualbox 2>&1 > /dev/null && echo $$?), 0)
-    AVAILABLE_BUILDERS += virtualbox-iso
-endif
-ifeq ($(shell which vmplayer 2>&1 > /dev/null && echo $$?), 0)
-    AVAILABLE_BUILDERS += vmware-iso
-endif
-BUILDER ?= $(firstword $(AVAILABLE_BUILDERS))
 
 ##
 #       Templates and flavors detection