diff --git a/lib/puppet/parser/functions/pcmk_nodes_added.rb b/lib/puppet/parser/functions/pcmk_nodes_added.rb
new file mode 100644
index 00000000..08073664
--- /dev/null
+++ b/lib/puppet/parser/functions/pcmk_nodes_added.rb
@@ -0,0 +1,54 @@
+module Puppet::Parser::Functions
+  newfunction(
+      :pcmk_nodes_added,
+      type: :rvalue,
+      arity: -1,
+      doc: <<-eof
+Input data cluster_members string separated by a space:
+* String 'n1 n2 n3'
+* Output of `crm_node -l` (only used to ease unit testing) (optional)
+
+Output forms:
+* array - output the plain array of nodes that have been added compared
+          to the running cluster. It returns an empty array in case the
+          cluster is not set up or if crm_node return an error
+      eof
+  ) do |args|
+    # no point in doing this if the crm_node executable does not exist
+    return [] if Facter::Util::Resolution.which('crm_node') == nil
+    nodes = args[0]
+    crm_node_list = args[1]
+    unless nodes.is_a? String
+      fail "Got unsupported nodes input data: #{nodes.inspect}"
+    end
+    if crm_node_list && !crm_node_list.kind_of?(String) then
+      fail "Got unsupported crm_node_list #{crm_node_list.inspect}"
+    end
+
+    if crm_node_list && crm_node_list.kind_of?(String) then
+      return [] if crm_node_list.empty?
+      crm_nodes_output = crm_node_list
+    else
+      # A typical crm_node -l output is like the following:
+      # [root@foobar-0 ~]# crm_node -l
+      # 3 foobar-2 member
+      # 1 foobar-0 member
+      # 2 foobar-1 lost
+      crm_nodes_output = `crm_node -l`
+      # if the command fails we certainly did not add any nodes
+      return [] if $?.exitstatus != 0
+    end
+
+    crm_nodes = []
+    crm_nodes_output.lines.each { |line|
+      (id, node, state, _) = line.split(" ").collect(&:strip)
+      valid_states = %w(member lost)
+      state.downcase! if state
+      crm_nodes.push(node.strip) if valid_states.include? state
+    }
+    cluster_nodes = nodes.split(" ")
+    nodes_added = cluster_nodes - crm_nodes
+    Puppet.debug("pcmk_nodes_added: #{nodes_added}")
+    nodes_added
+  end
+end
diff --git a/manifests/corosync.pp b/manifests/corosync.pp
index e9a77829..472970af 100644
--- a/manifests/corosync.pp
+++ b/manifests/corosync.pp
@@ -176,6 +176,34 @@ class pacemaker::corosync(
   }
 
   if $setup_cluster {
+    # Detect if we are trying to add some nodes by comparing
+    # $cluster_members and the actual running nodes in the cluster
+    $nodes_added = pcmk_nodes_added($cluster_members)
+    # If we're rerunning this puppet manifest and $cluster_members
+    # contains more nodes than the currently running cluster
+    if count($nodes_added) > 0 {
+      $nodes_added.each |$node_to_add| {
+        exec {"Adding Cluster node: ${node_to_add} to Cluster ${cluster_name}":
+          unless    => "${::pacemaker::pcs_bin} status 2>&1 | grep -e \"^Online:.* ${node_to_add} .*\"",
+          command   => "${::pacemaker::pcs_bin} cluster node add ${node_to_add} --wait",
+          timeout   => $cluster_start_timeout,
+          tries     => $cluster_start_tries,
+          try_sleep => $cluster_start_try_sleep,
+          notify    => Exec["node-cluster-start-${node_to_add}"],
+          tag       => 'pacemaker-scaleup',
+        }
+        exec {"node-cluster-start-${node_to_add}":
+          unless      => "${::pacemaker::pcs_bin} status 2>&1 | grep -e \"^Online:.* ${node_to_add} .*\"",
+          command     => "${::pacemaker::pcs_bin} cluster start ${node_to_add} --wait",
+          timeout     => $cluster_start_timeout,
+          tries       => $cluster_start_tries,
+          try_sleep   => $cluster_start_try_sleep,
+          refreshonly => true,
+          tag         => 'pacemaker-scaleup',
+        }
+      }
+      Exec <|tag == 'pacemaker-auth'|> -> Exec <|tag == 'pacemaker-scaleup'|>
+    }
 
     if ! $cluster_members_rrp {
       $cluster_members_rrp_real = $cluster_members
diff --git a/spec/functions/pcmk_nodes_added_spec.rb b/spec/functions/pcmk_nodes_added_spec.rb
new file mode 100644
index 00000000..0eab59bb
--- /dev/null
+++ b/spec/functions/pcmk_nodes_added_spec.rb
@@ -0,0 +1,31 @@
+require 'spec_helper'
+
+describe 'pcmk_nodes_added' do
+  context 'interface' do
+    it { is_expected.not_to eq(nil) }
+    it { is_expected.to run.with_params(1).and_raise_error(Puppet::Error, /Got unsupported nodes input data/) }
+    it { is_expected.to run.with_params('foo', []).and_raise_error(Puppet::Error, /Got unsupported crm_node_list/) }
+  end
+
+  it 'returns no added nodes because cluster is not set up' do
+    is_expected.to run.with_params('foo', '').and_return([])
+    is_expected.to run.with_params('foo bar', '').and_return([])
+    is_expected.to run.with_params('', '').and_return([])
+  end
+
+  it 'returns added nodes when cluster is fully up' do
+    crm_out = "\n3 ctr-2 member\n2 ctr-1 member\n1 ctr-0 member\n"
+    is_expected.to run.with_params('ctr-0 ctr-1 ctr-2', crm_out).and_return([])
+    is_expected.to run.with_params('ctr-0 ctr-1 ctr-2 ctr-3', crm_out).and_return(['ctr-3'])
+    is_expected.to run.with_params('ctr-1 ctr-3 ctr-2', crm_out).and_return(['ctr-3'])
+    is_expected.to run.with_params('', crm_out).and_return([])
+  end
+
+  it 'returns added nodes when cluster is not fully up' do
+    crm_out = "\n3 ctr-2 lost\n2 ctr-1 member\n1 ctr-0 member\n"
+    is_expected.to run.with_params('ctr-0 ctr-1 ctr-2', crm_out).and_return([])
+    is_expected.to run.with_params('ctr-0 ctr-1 ctr-2 ctr-3', crm_out).and_return(['ctr-3'])
+    is_expected.to run.with_params('ctr-1 ctr-3 ctr-2', crm_out).and_return(['ctr-3'])
+    is_expected.to run.with_params('', crm_out).and_return([])
+  end
+end