[Releng] Uses newer jar signer version.
diff --git a/model/org.eclipse.justj.model/pom.xml b/model/org.eclipse.justj.model/pom.xml
index fd00f79..262ab42 100644
--- a/model/org.eclipse.justj.model/pom.xml
+++ b/model/org.eclipse.justj.model/pom.xml
@@ -23,7 +23,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <tycho-version>1.7.0</tycho-version>
-    <jarsigner-version>1.1.7</jarsigner-version>
+    <jarsigner-version>1.3.1</jarsigner-version>
     <justj.tools.repo>https://download.eclipse.org/justj/tools/updates/nightly/latest</justj.tools.repo>
     <eclipse.repo>https://download.eclipse.org/releases/2020-06</eclipse.repo>
     <os-jvm-flags/>
diff --git a/releng/org.eclipse.justj.releng/index/pom.xml b/releng/org.eclipse.justj.releng/index/pom.xml
index 8119324..d32773e 100644
--- a/releng/org.eclipse.justj.releng/index/pom.xml
+++ b/releng/org.eclipse.justj.releng/index/pom.xml
@@ -23,7 +23,7 @@
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <tycho-version>1.7.0</tycho-version>
-    <jarsigner-version>1.1.7</jarsigner-version>
+    <jarsigner-version>1.3.1</jarsigner-version>
     <justj.tools.repo>https://download.eclipse.org/justj/tools/updates/nightly/latest</justj.tools.repo>
     <eclipse.repo>https://download.eclipse.org/releases/2020-06</eclipse.repo>
     <justj.manifest.location>justj.manifest</justj.manifest.location>