diff --git a/atomic-cache-checksum.patch b/atomic-cache-checksum.patch
new file mode 100644
index 0000000..68899a3
--- /dev/null
+++ b/atomic-cache-checksum.patch
@@ -0,0 +1,27 @@
+diff -rup createrepo-0.9.5-orig/createrepo/yumbased.py createrepo-0.9.5/createrepo/yumbased.py
+--- createrepo-0.9.5-orig/createrepo/yumbased.py	2008-02-18 15:30:13.000000000 -0500
++++ createrepo-0.9.5/createrepo/yumbased.py	2008-10-08 12:36:14.000000000 -0400
+@@ -30,6 +30,7 @@ from rpmUtils.transaction import initRea
+ from rpmUtils.miscutils import flagToString, stringToVersion
+ import libxml2
+ import utils
++import tempfile
+ 
+ #FIXME - merge into class with config stuff
+ fileglobs = ['.*bin\/.*', '^\/etc\/.*', '^\/usr\/lib\/sendmail$']
+@@ -106,9 +107,13 @@ class CreateRepoPackage(YumLocalPackage)
+              
+         else:
+             checksum = misc.checksum('sha', self.localpath)
+-            csumo = open(csumfile, 'w')
++
++            #  This is atomic cache creation via. rename, so we can have two
++            # tasks using the same cachedir ... mash does this.
++            csumo = tempfile.NamedTemporaryFile(mode='w', dir=self.crp_cachedir)
+             csumo.write(checksum)
+             csumo.close()
++            os.rename(csumo.name, csumfile)
+         
+         self._checksum = checksum
+ 
+Only in createrepo-0.9.5/createrepo: yumbased.py~
diff --git a/createrepo.spec b/createrepo.spec
index 1e74075..bdce153 100644
--- a/createrepo.spec
+++ b/createrepo.spec
@@ -3,12 +3,13 @@
 Summary: Creates a common metadata repository
 Name: createrepo
 Version: 0.9.5
-Release: 2%{?dist}
+Release: 3%{?dist}
 License: GPLv2
 Group: System Environment/Base
 Source: %{name}-%{version}.tar.gz
 Patch0: ten-changelog-limit.patch
 Patch1:	empty-pkgid-raise.patch
+Patch2:	atomic-cache-checksum.patch
 URL: http://linux.duke.edu/projects/metadata/
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 BuildArchitectures: noarch
@@ -24,6 +25,7 @@ packages.
 %setup -q
 %patch0 -p0
 %patch1 -p0
+%patch2 -p1
 
 %build
 
@@ -45,6 +47,9 @@ rm -rf $RPM_BUILD_ROOT
 %{python_sitelib}/createrepo
 
 %changelog
+* Wed Oct  8 2008 James Antill <james@fedoraproject.org> - 0.9.5-3
+- Do atomic updates to the cachedir, for parallel runs
+
 * Fri Feb 22 2008 Seth Vidal <skvidal at fedoraproject.org> - 0.9.5-2
 - patch for the mistake in the raise for an empty pkgid