diff --git a/build.xml b/build.xml
index d7ce3062..c9feebce 100644
--- a/build.xml
+++ b/build.xml
@@ -207,25 +207,7 @@
 		<fileset id="jar.classpath" dir="${dir.lib}" includesfile="${dir.lib}/jar.includes" />
 
 		<!-- rebuild each dependency jar with zero compression and remove signatures -->
-		<groovy>
-			def destfile = { r -> 
-				ant.project.properties.'dir.dist' + '/lib/' + r.file.name.replaceAll(/.jdk15on|.java16/, '').toLowerCase()
-			}
-
-			project.references.'jar.classpath'.each { r ->
-				ant.jar(destfile: destfile(r), index: 'yes', indexMetaInf: 'yes', compress: 'no') {
-					zipfileset(src: r) {
-						exclude(name: 'META-INF/MANIFEST.MF')
-						exclude(name: 'META-INF/INDEX.LIST')
-						exclude(name: 'META-INF/*.RSA')
-						exclude(name: 'META-INF/*.DSA')
-						exclude(name: 'META-INF/*.SF')
-						exclude(name: 'META-INF/*.EC')
-					}
-				}
-			}
-		</groovy>
-
+		<groovy src="${dir.lib}/jar.groovy" />
 
 		<path id="jar.classpath">
 			<fileset dir="${dir.dist}/lib">
diff --git a/lib/jar.groovy b/lib/jar.groovy
new file mode 100644
index 00000000..a8137abc
--- /dev/null
+++ b/lib/jar.groovy
@@ -0,0 +1,16 @@
+def destfile = { r -> 
+	ant.project.properties.'dir.dist' + '/lib/' + r.file.name.replaceAll(/.jdk15on|.java16/, '').toLowerCase()
+}
+
+project.references.'jar.classpath'.each { r ->
+	ant.jar(destfile: destfile(r), index: 'yes', indexMetaInf: 'yes', compress: 'no') {
+		zipfileset(src: r) {
+			exclude(name: 'META-INF/MANIFEST.MF')
+			exclude(name: 'META-INF/INDEX.LIST')
+			exclude(name: 'META-INF/*.RSA')
+			exclude(name: 'META-INF/*.DSA')
+			exclude(name: 'META-INF/*.SF')
+			exclude(name: 'META-INF/*.EC')
+		}
+	}
+}