diff --git a/lib/puppet/reports/store.rb b/lib/puppet/reports/store.rb
index 997206ec4..cd188fafd 100644
--- a/lib/puppet/reports/store.rb
+++ b/lib/puppet/reports/store.rb
@@ -1,60 +1,67 @@
 require 'puppet'
+require 'fileutils'
+require 'tempfile'
 
 Puppet::Reports.register_report(:store) do
   desc "Store the yaml report on disk.  Each host sends its report as a YAML dump
     and this just stores the file on disk, in the `reportdir` directory.
 
     These files collect quickly -- one every half hour -- so it is a good idea
     to perform some maintenance on them if you use this report (it's the only
     default report)."
 
   def process
     # We don't want any tracking back in the fs.  Unlikely, but there
     # you go.
     client = self.host.gsub("..",".")
 
     dir = File.join(Puppet[:reportdir], client)
 
     if ! FileTest.exists?(dir)
       FileUtils.mkdir_p(dir)
       FileUtils.chmod_R(0750, dir)
     end
 
     # Now store the report.
     now = Time.now.gmtime
     name = %w{year month day hour min}.collect do |method|
       # Make sure we're at least two digits everywhere
       "%02d" % now.send(method).to_s
     end.join("") + ".yaml"
 
     file = File.join(dir, name)
 
+    f = Tempfile.new(name, dir)
     begin
-      File.open(file, "w", 0640) do |f|
+      begin
+        f.chmod(0640)
         f.print to_yaml
+      ensure
+        f.close
       end
+      FileUtils.mv(f.path, file)
     rescue => detail
       puts detail.backtrace if Puppet[:trace]
       Puppet.warning "Could not write report for #{client} at #{file}: #{detail}"
     end
 
     # Only testing cares about the return value
     file
   end
 
   # removes all reports for a given host
   def self.destroy(host)
     client = host.gsub("..",".")
     dir = File.join(Puppet[:reportdir], client)
 
     if File.exists?(dir)
       Dir.entries(dir).each do |file|
         next if ['.','..'].include?(file)
         file = File.join(dir, file)
         File.unlink(file) if File.file?(file)
       end
       Dir.rmdir(dir)
     end
   end
 end
 
diff --git a/spec/unit/reports/store_spec.rb b/spec/unit/reports/store_spec.rb
index 73a7e353f..5b752c4b7 100755
--- a/spec/unit/reports/store_spec.rb
+++ b/spec/unit/reports/store_spec.rb
@@ -1,30 +1,48 @@
 #!/usr/bin/env rspec
 require 'spec_helper'
 
 require 'puppet/reports'
 require 'time'
+require 'pathname'
+require 'tempfile'
+require 'fileutils'
 
 processor = Puppet::Reports.report(:store)
 
 describe processor do
   describe "#process" do
     include PuppetSpec::Files
     before :each do
-      Puppet[:reportdir] = tmpdir('reports') << '/reports' 
+      Puppet[:reportdir] = File.join(tmpdir('reports'), 'reports')
       @report = YAML.load_file(File.join(PuppetSpec::FIXTURE_DIR, 'yaml/report2.6.x.yaml')).extend processor
     end
 
     it "should create a report directory for the client if one doesn't exist" do
       @report.process
 
       File.should be_directory(File.join(Puppet[:reportdir], @report.host))
     end
 
     it "should write the report to the file in YAML" do
       Time.stubs(:now).returns(Time.parse("2011-01-06 12:00:00 UTC"))
       @report.process
 
       File.read(File.join(Puppet[:reportdir], @report.host, "201101061200.yaml")).should == @report.to_yaml
     end
+
+    it "should write to the report directory in the correct sequence" do
+      # By doing things in this sequence we should protect against race
+      # conditions
+      Time.stubs(:now).returns(Time.parse("2011-01-06 12:00:00 UTC"))
+      writeseq = sequence("write")
+      file = mock "file"
+      Tempfile.expects(:new).in_sequence(writeseq).returns(file)
+      file.expects(:chmod).in_sequence(writeseq).with(0640)
+      file.expects(:print).with(@report.to_yaml).in_sequence(writeseq)
+      file.expects(:close).in_sequence(writeseq)
+      file.stubs(:path).returns(File.join(Dir.tmpdir, "foo123"))
+      FileUtils.expects(:mv).in_sequence(writeseq).with(File.join(Dir.tmpdir, "foo123"), File.join(Puppet[:reportdir], @report.host, "201101061200.yaml"))
+      @report.process
+    end
   end
 end