diff --git a/lib/vmpooler/vsphere_helper.rb b/lib/vmpooler/vsphere_helper.rb
index 4e55583..45b5ab7 100644
--- a/lib/vmpooler/vsphere_helper.rb
+++ b/lib/vmpooler/vsphere_helper.rb
@@ -178,11 +178,10 @@ module Vmpooler
       base = datacenter.vmFolder
       folders = foldername.split('/')
       folders.each do |folder|
-        case base
-          when RbVmomi::VIM::Folder
-            base = base.childEntity.find { |f| f.name == folder }
-          else
-            abort "Unexpected object type encountered (#{base.class}) while finding folder"
+        if base.is_a? RbVmomi::VIM::Folder
+          base = base.childEntity.find { |f| f.name == folder }
+        else
+          abort "Unexpected object type encountered (#{base.class}) while finding folder"
         end
       end