diff --git a/lib/puppet/util/pidlock.rb b/lib/puppet/util/pidlock.rb
index 066f66e52..fcf0cf296 100644
--- a/lib/puppet/util/pidlock.rb
+++ b/lib/puppet/util/pidlock.rb
@@ -1,68 +1,72 @@
 require 'fileutils'
 
 class Puppet::Util::Pidlock
   attr_reader :lockfile
 
   def initialize(lockfile)
     @lockfile = lockfile
   end
 
   def locked?
     clear_if_stale
     File.exists? @lockfile
   end
 
   def mine?
     Process.pid == lock_pid
   end
 
   def anonymous?
     return false unless File.exists?(@lockfile)
     File.read(@lockfile) == ""
   end
 
   def lock(opts = {})
     opts = {:anonymous => false}.merge(opts)
 
     if locked?
       mine?
     else
       if opts[:anonymous]
         File.open(@lockfile, 'w') { |fd| true }
       else
         File.open(@lockfile, "w") { |fd| fd.write(Process.pid) }
       end
       true
     end
   end
 
   def unlock(opts = {})
     opts = {:anonymous => false}.merge(opts)
 
     if mine? or (opts[:anonymous] and anonymous?)
       File.unlink(@lockfile)
       true
     else
       false
     end
   end
 
   private
   def lock_pid
     if File.exists? @lockfile
       File.read(@lockfile).to_i
     else
       nil
     end
   end
 
   def clear_if_stale
     return if lock_pid.nil?
 
+    errors = [Errno::ESRCH]
+    # Process::Error can only happen, and is only defined, on Windows
+    errors << Process::Error if defined? Process::Error
+
     begin
       Process.kill(0, lock_pid)
-    rescue Errno::ESRCH, Process::Error
+    rescue *errors
       File.unlink(@lockfile)
     end
   end
 end