diff --git a/cdist/conf/explorer/machine_type b/cdist/conf/explorer/machine_type
index 3a3cd0c1..bb21f69c 100755
--- a/cdist/conf/explorer/machine_type
+++ b/cdist/conf/explorer/machine_type
@@ -22,7 +22,7 @@
 
 # FIXME: other system types (not linux ...)
 
-if [ -d "/proc/vz" -a ! -d "/proc/bc" ]; then
+if [ -d "/proc/vz" ] && [ ! -d "/proc/bc" ]; then
     echo openvz
     exit
 fi