diff --git a/build.xml b/build.xml
index d3d9872..28ace36 100755
--- a/build.xml
+++ b/build.xml
@@ -213,7 +213,7 @@
         <pathelement location="${gwt.build.out}/tools/api-checker/bin"/>
         <fileset dir="${gwt.build.lib}" includes="gwt-user.jar,gwt-dev.jar"/>
         <pathelement path="${java.class.path}"/>
-        <pathelement location="${gwt.tools.lib}/apache/ant-1.6.5.jar"/>
+        <pathelement location="${gwt.tools.lib}/apache/ant-zipscanner/ant-zipscanner-1.6.5-1-rebased.jar"/>
         <pathelement location="${gwt.tools.lib}/javax/validation/validation-api-1.0.0.GA.jar"/>
         <pathelement
             location="${gwt.tools.lib}/hibernate/validator/hibernate-validator-4.1.0.Final.jar"/>
diff --git a/dev/build.xml b/dev/build.xml
index aff5977..e65df23 100755
--- a/dev/build.xml
+++ b/dev/build.xml
@@ -73,7 +73,7 @@
       <sourcefiles>
         <fileset dir="${gwt.tools.lib}">
           <include name="apache/tapestry-util-text-4.0.2.jar"/>
-          <include name="apache/ant-1.6.5.jar"/>
+          <include name="apache/ant-zipscanner/ant-zipscanner-1.6.5-1-rebased.jar"/>
           <include name="colt/colt-1.2.jar"/>
           <include name="eclipse/org.eclipse.jdt.core_3.17.0.v20190306-2240.jar"/>
           <include name="eclipse/jdtCompilerAdapter_3.17.0.v20190306-2240.jar"/>
@@ -133,7 +133,7 @@
           <zipfileset src="${gwt.tools.lib}/objectweb/asm-7.1/asm-commons-7.1.jar"/>
           <zipfileset src="${gwt.tools.lib}/objectweb/asm-7.1/asm-util-7.1.jar"/>
           <zipfileset src="${gwt.tools.lib}/apache/tapestry-util-text-4.0.2.jar"/>
-          <zipfileset src="${gwt.tools.lib}/apache/ant-1.6.5.jar"/>
+          <zipfileset src="${gwt.tools.lib}/apache/ant-zipscanner/ant-zipscanner-1.6.5-1-rebased.jar"/>
           <zipfileset src="${gwt.tools.lib}/colt/colt-1.2.jar"/>
           <zipfileset
               src="${gwt.tools.lib}/eclipse/org.eclipse.jdt.core_3.17.0.v20190306-2240.jar"/>
@@ -221,7 +221,7 @@
       <compilerarg value="-Xep:ReturnValueIgnored:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
       <compilerarg value="-Xep:EqualsIncompatibleType:OFF" compiler="com.google.errorprone.ErrorProneAntCompilerAdapter"/>
       <classpath>
-        <pathelement location="${gwt.tools.lib}/apache/ant-1.6.5.jar"/>
+        <pathelement location="${gwt.tools.lib}/apache/ant-zipscanner/ant-zipscanner-1.6.5-1-rebased.jar"/>
         <pathelement location="${gwt.tools.lib}/colt/colt-1.2.jar"/>
         <pathelement location="${gwt.tools.lib}/objectweb/asm-7.1/asm-7.1.jar"/>
         <pathelement location="${gwt.tools.lib}/objectweb/asm-7.1/asm-commons-7.1.jar"/>
diff --git a/dev/core/src/com/google/gwt/dev/resource/impl/DefaultFilters.java b/dev/core/src/com/google/gwt/dev/resource/impl/DefaultFilters.java
index d3aa1a8..f10fa81 100644
--- a/dev/core/src/com/google/gwt/dev/resource/impl/DefaultFilters.java
+++ b/dev/core/src/com/google/gwt/dev/resource/impl/DefaultFilters.java
@@ -15,14 +15,14 @@
  */
 package com.google.gwt.dev.resource.impl;
 
-import org.apache.tools.ant.types.ZipScanner;
+import com.google.gwt.thirdparty.apache.ant.types.ZipScanner;
 
 import java.util.regex.Pattern;
 
 /**
  * A singleton class that provides blazingly fast implementation of the default
- * excludes of Ant's {@link org.apache.tools.ant.DirectoryScanner}, assuming
- * case-sensitiveness.
+ * excludes of Ant's {@link com.google.gwt.thirdparty.apache.ant.DirectoryScanner},
+ * assuming case-sensitiveness.
  *
  * TODO: this class needs to be revisited, when Gwt's Ant is upgraded.
  *
diff --git a/dev/core/src/com/google/gwt/dev/resource/impl/PathPrefix.java b/dev/core/src/com/google/gwt/dev/resource/impl/PathPrefix.java
index 2631557..35bc921 100644
--- a/dev/core/src/com/google/gwt/dev/resource/impl/PathPrefix.java
+++ b/dev/core/src/com/google/gwt/dev/resource/impl/PathPrefix.java
@@ -15,7 +15,7 @@
  */
 package com.google.gwt.dev.resource.impl;
 
-import org.apache.tools.ant.types.ZipScanner;
+import com.google.gwt.thirdparty.apache.ant.types.ZipScanner;
 
 import java.util.ArrayList;
 import java.util.HashSet;
diff --git a/dev/core/test/com/google/gwt/dev/resource/impl/DefaultFiltersTest.java b/dev/core/test/com/google/gwt/dev/resource/impl/DefaultFiltersTest.java
index fcd5a96..1f84956 100644
--- a/dev/core/test/com/google/gwt/dev/resource/impl/DefaultFiltersTest.java
+++ b/dev/core/test/com/google/gwt/dev/resource/impl/DefaultFiltersTest.java
@@ -19,7 +19,7 @@
 
 import junit.framework.TestCase;
 
-import org.apache.tools.ant.types.ZipScanner;
+import com.google.gwt.thirdparty.apache.ant.types.ZipScanner;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/maven/poms/gwt/gwt-dev/pom-template.xml b/maven/poms/gwt/gwt-dev/pom-template.xml
index 0e39df0..534ea4e 100644
--- a/maven/poms/gwt/gwt-dev/pom-template.xml
+++ b/maven/poms/gwt/gwt-dev/pom-template.xml
@@ -45,10 +45,6 @@
             </exclusions>
         </dependency>
         <dependency>
-            <groupId>ant</groupId>
-            <artifactId>ant</artifactId>
-        </dependency>
-        <dependency>
             <groupId>commons-collections</groupId>
             <artifactId>commons-collections</artifactId>
         </dependency>
diff --git a/maven/poms/gwt/pom-template.xml b/maven/poms/gwt/pom-template.xml
index 78d3e05..fd01c1c 100644
--- a/maven/poms/gwt/pom-template.xml
+++ b/maven/poms/gwt/pom-template.xml
@@ -106,11 +106,6 @@
                 <version>1.2.0</version>
             </dependency>
             <dependency>
-                <groupId>ant</groupId>
-                <artifactId>ant</artifactId>
-                <version>1.6.5</version>
-            </dependency>
-            <dependency>
                 <groupId>commons-collections</groupId>
                 <artifactId>commons-collections</artifactId>
                 <version>3.2.2</version>
diff --git a/tools/api-checker/src/com/google/gwt/tools/apichecker/ApiCompatibilityChecker.java b/tools/api-checker/src/com/google/gwt/tools/apichecker/ApiCompatibilityChecker.java
index bd00bc7..313037c 100644
--- a/tools/api-checker/src/com/google/gwt/tools/apichecker/ApiCompatibilityChecker.java
+++ b/tools/api-checker/src/com/google/gwt/tools/apichecker/ApiCompatibilityChecker.java
@@ -28,7 +28,7 @@
 import com.google.gwt.util.tools.ArgHandlerString;
 import com.google.gwt.util.tools.ToolBase;
 
-import org.apache.tools.ant.types.ZipScanner;
+import com.google.gwt.thirdparty.apache.ant.types.ZipScanner;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedReader;