diff --git a/lib/puppet/parser/functions/postgresql_password.rb b/lib/puppet/parser/functions/postgresql_password.rb
index 0689e0e..e5d2620 100644
--- a/lib/puppet/parser/functions/postgresql_password.rb
+++ b/lib/puppet/parser/functions/postgresql_password.rb
@@ -1,18 +1,18 @@
 # hash a string as mysql's "PASSWORD()" function would do it
 require 'digest/md5'
 
 module Puppet::Parser::Functions
   newfunction(:postgresql_password, :type => :rvalue, :doc => <<-EOS
     Returns the postgresql password hash from the clear text username / password.
     EOS
   ) do |args|
 
     raise(Puppet::ParseError, "postgresql_password(): Wrong number of arguments " +
       "given (#{args.size} for 2)") if args.size != 2
 
     username = args[0]
     password = args[1]
 
-    'md5' + Digest::MD5.hexdigest(password + username)
+    'md5' + Digest::MD5.hexdigest(password.to_s + username.to_s)
   end
 end
diff --git a/spec/unit/functions/postgresql_password_spec.rb b/spec/unit/functions/postgresql_password_spec.rb
index b5aa00b..89699f6 100644
--- a/spec/unit/functions/postgresql_password_spec.rb
+++ b/spec/unit/functions/postgresql_password_spec.rb
@@ -1,6 +1,8 @@
 require 'spec_helper'
 
 describe 'postgresql_password', :type => :puppet_function do
   it { is_expected.to run.with_params('foo', 'bar').
     and_return('md596948aad3fcae80c08a35c9b5958cd89') }
+  it { is_expected.to run.with_params('foo', 1234).
+    and_return('md539a0e1b308278a8de5e007cd1f795920') }
 end