diff --git a/build.xml b/build.xml
index bd6e7866b..7101c5151 100644
--- a/build.xml
+++ b/build.xml
@@ -241,6 +241,7 @@
       <filename name="${optional.package}/script/**/*"/>
       <filename name="${optional.type.package}/*Script*"/>
       <filename name="${util.package}/Script*"/>
+      <filename name="${util.package}/optional/Script*"/>
     </or>
   </selector>
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/Definer.java b/src/main/org/apache/tools/ant/taskdefs/Definer.java
index 34fbbff9c..3c30ac4d8 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Definer.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Definer.java
@@ -462,6 +462,30 @@ public abstract class Definer extends DefBase {
         this.resource = res;
     }
 
+    /**
+     * Antlib attribute, sets resource and uri.
+     * uri is set the antlib value and, resource is set
+     * to the antlib.xml resource in the classpath.
+     * For example antlib="antlib:org.acme.bland.cola"
+     * corresponds to uri="antlib:org.acme.bland.cola"
+     * resource="org/acme/bland/cola/antlib.xml".
+     * ASF Bugzilla Bug 31999
+     * @param antlib the value to set.
+     */
+    public void setAntlib(String antlib) {
+        if (definerSet) {
+            tooManyDefinitions();
+        }
+        if (!antlib.startsWith("antlib:")) {
+            throw new BuildException(
+                "Invalid antlib attribute - it must start with antlib:");
+        }
+        setURI(antlib);
+        this.resource = antlib.substring("antlib:".length()).replace('.','/')
+            + "/antlib.xml";
+        definerSet = true;
+    }
+
     /**
      * Name of the definition
      * @param name the name of the definition
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/Script.java b/src/main/org/apache/tools/ant/taskdefs/optional/Script.java
index 94721e064..fccca0b5f 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/Script.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/Script.java
@@ -20,7 +20,7 @@ package org.apache.tools.ant.taskdefs.optional;
 import java.io.File;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Task;
-import org.apache.tools.ant.util.ScriptRunner;
+import org.apache.tools.ant.util.optional.ScriptRunner;
 import org.apache.tools.ant.types.Path;
 import org.apache.tools.ant.types.Reference;
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/optional/script/ScriptDef.java b/src/main/org/apache/tools/ant/taskdefs/optional/script/ScriptDef.java
index f377d1a34..fc7a6cbf6 100644
--- a/src/main/org/apache/tools/ant/taskdefs/optional/script/ScriptDef.java
+++ b/src/main/org/apache/tools/ant/taskdefs/optional/script/ScriptDef.java
@@ -36,7 +36,7 @@ import java.util.HashSet;
 import java.io.File;
 
 import org.apache.tools.ant.util.ClasspathUtils;
-import org.apache.tools.ant.util.ScriptRunner;
+import org.apache.tools.ant.util.optional.ScriptRunner;
 
 /**
  * Define a task using a script
diff --git a/src/main/org/apache/tools/ant/types/optional/AbstractScriptComponent.java b/src/main/org/apache/tools/ant/types/optional/AbstractScriptComponent.java
index 4a2c13f95..83d0beaf0 100644
--- a/src/main/org/apache/tools/ant/types/optional/AbstractScriptComponent.java
+++ b/src/main/org/apache/tools/ant/types/optional/AbstractScriptComponent.java
@@ -18,7 +18,7 @@
 package org.apache.tools.ant.types.optional;
 
 import org.apache.tools.ant.ProjectComponent;
-import org.apache.tools.ant.util.ScriptRunner;
+import org.apache.tools.ant.util.optional.ScriptRunner;
 
 import java.io.File;
 
diff --git a/src/main/org/apache/tools/ant/types/optional/ScriptFilter.java b/src/main/org/apache/tools/ant/types/optional/ScriptFilter.java
index 0cd86bd78..a0b9ac5cd 100644
--- a/src/main/org/apache/tools/ant/types/optional/ScriptFilter.java
+++ b/src/main/org/apache/tools/ant/types/optional/ScriptFilter.java
@@ -20,7 +20,7 @@ package org.apache.tools.ant.types.optional;
 import org.apache.tools.ant.filters.TokenFilter;
 import java.io.File;
 import org.apache.tools.ant.BuildException;
-import org.apache.tools.ant.util.ScriptRunner;
+import org.apache.tools.ant.util.optional.ScriptRunner;
 
 
 /**
diff --git a/src/main/org/apache/tools/ant/types/optional/ScriptSelector.java b/src/main/org/apache/tools/ant/types/optional/ScriptSelector.java
index 1d282dadf..0a75c4490 100644
--- a/src/main/org/apache/tools/ant/types/optional/ScriptSelector.java
+++ b/src/main/org/apache/tools/ant/types/optional/ScriptSelector.java
@@ -18,7 +18,7 @@
 package org.apache.tools.ant.types.optional;
 
 import org.apache.tools.ant.types.selectors.BaseSelector;
-import org.apache.tools.ant.util.ScriptRunner;
+import org.apache.tools.ant.util.optional.ScriptRunner;
 import org.apache.tools.ant.BuildException;
 
 import java.io.File;
diff --git a/src/main/org/apache/tools/ant/util/ScriptRunner.java b/src/main/org/apache/tools/ant/util/optional/ScriptRunner.java
similarity index 98%
rename from src/main/org/apache/tools/ant/util/ScriptRunner.java
rename to src/main/org/apache/tools/ant/util/optional/ScriptRunner.java
index 641d33eec..0bae5bbb3 100644
--- a/src/main/org/apache/tools/ant/util/ScriptRunner.java
+++ b/src/main/org/apache/tools/ant/util/optional/ScriptRunner.java
@@ -15,7 +15,7 @@
  *  limitations under the License.
  *
  */
-package org.apache.tools.ant.util;
+package org.apache.tools.ant.util.optional;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -29,6 +29,8 @@ import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.ProjectComponent;
 import org.apache.tools.ant.Project;
 
+import org.apache.tools.ant.util.FileUtils;
+
 import java.util.Map;
 import java.util.HashMap;
 import java.util.Iterator;