diff --git a/src/oca/ruby/OpenNebula/XMLUtils.rb b/src/oca/ruby/OpenNebula/XMLUtils.rb
index 261e447b8c..9444a4c098 100644
--- a/src/oca/ruby/OpenNebula/XMLUtils.rb
+++ b/src/oca/ruby/OpenNebula/XMLUtils.rb
@@ -8,6 +8,13 @@ module OpenNebula
         NOKOGIRI=false
     end
 
+    begin
+        require 'rexml/formatters/pretty'
+        REXML_FORMATTERS=true
+    rescue LoadError
+        REXML_FORMATTERS=false
+    end
+
     ###########################################################################
     # The XMLElement class provides an abstraction of the underlying
     # XML parser engine. It provides XML-related methods for the Pool and
@@ -176,17 +183,20 @@ module OpenNebula
         end
 
         def to_xml(pretty=false)
-            if NOKOGIRI
-                @xml.to_xml
+            if NOKOGIRI && pretty
+                str = @xml.to_xml
+            elsif REXML_FORMATTERS && pretty
+                str = String.new
+
+                formatter = REXML::Formatters::Pretty.new
+                formatter.compact = true
+
+                formatter.write(@xml,str)
             else
-                str = ""
-                if pretty
-                    REXML::Formatters::Pretty.new(1).write(@xml,str)
-                else
-                    REXML::Formatters::Default.new.write(@xml,str)
-                end
-                str
+                str = @xml.to_s
             end
+
+            return str
         end
     end