diff --git a/.travis.yml b/.travis.yml
index 86e150fe..552d7596 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,8 @@ matrix:
     # Build with latest ruby
     - rvm: 2.5
       env: RUBOCOP_TEST="false" RSPEC_TEST="true" PUPPET_VERSIONS="5.5.8"
+    - rvm: 2.5
+      env: RUBOCOP_TEST="true" RSPEC_TEST="true" PUPPET_VERSIONS="6.18.0"
     # Puppet supports ruby 2.0 and 2.1 with Puppet 4.x, but build with more recent versions too
     - rvm: 2.3
       env: RUBOCOP_TEST="false" RSPEC_TEST="true" PUPPET_VERSIONS="4.10.10"
diff --git a/lib/octocatalog-diff/catalog-util/command.rb b/lib/octocatalog-diff/catalog-util/command.rb
index edb8c398..4e00c8e0 100644
--- a/lib/octocatalog-diff/catalog-util/command.rb
+++ b/lib/octocatalog-diff/catalog-util/command.rb
@@ -22,6 +22,8 @@ def initialize(options = {}, logger = nil)
         @node = options[:node]
         raise ArgumentError, 'Node must be specified to compile catalog' if @node.nil? || !@node.is_a?(String)
 
+        @puppet_version = options[:puppet_version]
+
         # To be initialized on-demand
         @puppet_argv = nil
         @puppet_binary = nil
@@ -56,7 +58,12 @@ def setup
 
         # Node to compile
         cmdline = []
-        cmdline.concat ['master', '--compile', Shellwords.escape(@node)]
+
+        if Gem::Version.new(@puppet_version) >= Gem::Version.new('6.0.0')
+          cmdline.concat ['catalog', 'compile', Shellwords.escape(@node)]
+        else
+          cmdline.concat ['master', '--compile', Shellwords.escape(@node)]
+        end
 
         # storeconfigs?
         if @options[:storeconfigs]
@@ -95,7 +102,7 @@ def setup
           --no-daemonize
           --no-ca
           --color=false
-          --config_version="/bin/echo catalogscript"
+          --config_version="/usr/bin/true"
         )
 
         # Add environment - only make this variable if preserve_environments is used.
diff --git a/lib/octocatalog-diff/catalog/computed.rb b/lib/octocatalog-diff/catalog/computed.rb
index a4d00fd8..d463d794 100644
--- a/lib/octocatalog-diff/catalog/computed.rb
+++ b/lib/octocatalog-diff/catalog/computed.rb
@@ -145,6 +145,7 @@ def puppet_command_obj
             compilation_dir: @builddir.tempdir,
             parser: @options.fetch(:parser, :default),
             puppet_binary: @puppet_binary,
+            puppet_version: puppet_version,
             fact_file: @builddir.fact_file,
             dir: @builddir.tempdir,
             enc: @builddir.enc