diff --git a/groovy18-timestamp.patch b/groovy18-timestamp.patch
index e795acf..220f92a 100644
--- a/groovy18-timestamp.patch
+++ b/groovy18-timestamp.patch
@@ -22,6 +22,24 @@
  
      public void visit(ASTNode[] astNodes, SourceUnit sourceUnit) {
  
+--- groovy-core-GROOVY_1_8_9/src/main/org/codehaus/groovy/classgen/Verifier.java	2023-09-15 00:14:26.176051747 +0200
++++ groovy-core-GROOVY_1_8_9/src/main/org/codehaus/groovy/classgen/Verifier.java	2023-09-15 00:14:20.536016445 +0200
+@@ -432,13 +432,13 @@
+                     ClassHelper.long_TYPE,
+                     //"",
+                     node,
+-                    new ConstantExpression(System.currentTimeMillis()));
++                    new ConstantExpression((System.getenv("SOURCE_DATE_EPOCH") != null ? new Date(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH"))) : new Date()).getTime()));
+             // alternatively, FieldNode timeTagField = SourceUnit.createFieldNode("public static final long __timeStamp = " + System.currentTimeMillis() + "L");
+             timeTagField.setSynthetic(true);
+             node.addField(timeTagField);
+ 
+             timeTagField = new FieldNode(
+-                    Verifier.__TIMESTAMP__ + String.valueOf(System.currentTimeMillis()),
++                    Verifier.__TIMESTAMP__ + String.valueOf((System.getenv("SOURCE_DATE_EPOCH") != null ? new Date(1000 * Long.parseLong(System.getenv("SOURCE_DATE_EPOCH"))) : new Date()).getTime()),
+                     ACC_PUBLIC | ACC_STATIC | ACC_SYNTHETIC,
+                     ClassHelper.long_TYPE,
+                     //"",
 --- groovy-core-GROOVY_1_8_9/src/main/org/codehaus/groovy/tools/groovydoc/gstringTemplates/classLevel/classDocName.html	2023-09-14 17:55:59.569563087 +0200
 +++ groovy-core-GROOVY_1_8_9/src/main/org/codehaus/groovy/tools/groovydoc/gstringTemplates/classLevel/classDocName.html	2023-09-14 21:15:34.220475678 +0200
 @@ -62,9 +62,8 @@
diff --git a/groovy18.spec b/groovy18.spec
index 63a293f..c0ec125 100644
--- a/groovy18.spec
+++ b/groovy18.spec
@@ -190,7 +190,7 @@ export CLASSPATH=$(build-classpath ant/ant-antlr)
 %if %{?pkg_vcmp:%pkg_vcmp java-devel >= 9}%{!?pkg_vcmp:0}
 export ANT_OPTS="--add-opens=java.base/java.lang=ALL-UNNAMED"
 %endif
-%ant -v -DskipTests=on -DskipExamples=on -DskipFetch=on -DskipEmbeddable=on \
+%ant -DskipTests=on -DskipExamples=on -DskipFetch=on -DskipEmbeddable=on \
         createJars javadoc
 
 %install