diff --git a/lib/mixlib/shellout/helper.rb b/lib/mixlib/shellout/helper.rb
index c9e64a2..e1cb2f2 100644
--- a/lib/mixlib/shellout/helper.rb
+++ b/lib/mixlib/shellout/helper.rb
@@ -149,10 +149,14 @@ def __clean_array(*args)
       # @param args [String] variable number of string arguments
       # @return [String] merged string
       #
-      def __join_whitespace(*args)
-        args.flatten.map do |arg|
-          arg.strip!
-          arg.include?(" ") ? sprintf('"%s"', arg) : arg
+      def __join_whitespace(*args, quote: false)
+        args.map do |arg|
+          if arg.is_a?(Array)
+            __join_whitespace(*arg, quote: arg.count > 1)
+          else
+            arg = arg.include?(" ") ? sprintf('"%s"', arg) : arg if quote
+            arg.strip
+          end
         end.join(" ")
       end
 
@@ -168,7 +172,7 @@ def __shell_out_command(*args, **options)
             if options[:input]
               command.concat "<<'COMMANDINPUT'\n"
               command.concat __join_whitespace(options[:input])
-              command.concat "COMMANDINPUT\n"
+              command.concat "\nCOMMANDINPUT\n"
             end
           end