diff --git a/hamcrest.spec b/hamcrest.spec
index 5383806..a0ee1b4 100644
--- a/hamcrest.spec
+++ b/hamcrest.spec
@@ -30,7 +30,7 @@
 
 Name:           hamcrest
 Version:        1.3
-Release:        21%{?dist}
+Release:        22%{?dist}
 Epoch:          0
 Summary:        Library of matchers for building test expressions
 License:        BSD
@@ -124,34 +124,11 @@ export OPT_JAR_LIST="junit ant/ant-junit"
 ant -Dant.build.javac.source=1.5 -Dversion=%{version} -Dbuild.sysclasspath=last clean core generator library bigjar javadoc
 
 # inject OSGi manifests
-mkdir -p META-INF
-cp -p %{SOURCE8} META-INF/MANIFEST.MF
-touch META-INF/MANIFEST.MF
-zip -u build/%{name}-core-%{version}.jar META-INF/MANIFEST.MF
-
-rm -fr META-INF
-mkdir -p META-INF
-cp -p %{SOURCE9} META-INF/MANIFEST.MF
-touch META-INF/MANIFEST.MF
-zip -u build/%{name}-library-%{version}.jar META-INF/MANIFEST.MF
-
-rm -fr META-INF
-mkdir -p META-INF
-cp -p %{SOURCE10} META-INF/MANIFEST.MF
-touch META-INF/MANIFEST.MF
-zip -u build/%{name}-text-%{version}.jar META-INF/MANIFEST.MF
-
-rm -fr META-INF
-mkdir -p META-INF
-cp -p %{SOURCE11} META-INF/MANIFEST.MF
-touch META-INF/MANIFEST.MF
-zip -u build/%{name}-integration-%{version}.jar META-INF/MANIFEST.MF
-
-rm -fr META-INF
-mkdir -p META-INF
-cp -p %{SOURCE12} META-INF/MANIFEST.MF
-touch META-INF/MANIFEST.MF
-zip -u build/%{name}-generator-%{version}.jar META-INF/MANIFEST.MF
+jar ufm build/%{name}-core-%{version}.jar %{SOURCE8}
+jar ufm build/%{name}-library-%{version}.jar %{SOURCE9}
+#jar ufm build/%{name}-text-%{version}.jar %{SOURCE10}
+jar ufm build/%{name}-integration-%{version}.jar %{SOURCE11}
+jar ufm build/%{name}-generator-%{version}.jar %{SOURCE12}
 
 %install
 sed -i 's/@VERSION@/%{version}/g' pom/*.pom
@@ -188,6 +165,10 @@ cp -pr %{name}-examples $RPM_BUILD_ROOT%{_datadir}/%{name}/
 %{_datadir}/%{name}
 
 %changelog
+* Mon Sep 25 2017 Mikolaj Izdebski <mizdebsk@redhat.com> - 0:1.3-22
+- Elimitate race condition when injecting JAR manifest
+- Resolves: rhbz#1495234
+
 * Wed Jul 26 2017 Fedora Release Engineering <releng@fedoraproject.org> - 0:1.3-21
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_27_Mass_Rebuild