diff --git a/dev/build.xml b/dev/build.xml
index 8922892..66e97ac 100755
--- a/dev/build.xml
+++ b/dev/build.xml
@@ -32,7 +32,7 @@
         <pathelement location="${gwt.tools.lib}/junit/junit-4.8.2.jar"/>
       </classpath>
     </gwt.javac>
-    <gwt.javac srcdir="" destdir="${javac.junit.out}" excludes="**/EmulatedCharset.java">
+    <gwt.javac srcdir="" destdir="${javac.junit.out}" excludes="**/EmulatedCharset.java,**/HashCodes.java">
       <src path="${gwt.root}/user/src" />
       <src path="${gwt.root}/user/super/com/google/gwt/emul/javaemul/internal"/>
       <classpath>
diff --git a/user/build.xml b/user/build.xml
index 7769964..79f2fcf 100755
--- a/user/build.xml
+++ b/user/build.xml
@@ -104,7 +104,7 @@
   <target name="compile" description="Compile all class files"
           unless="compile.complete">
     <mkdir dir="${javac.out}"/>
-    <gwt.javac excludes="**/EmulatedCharset.java">
+    <gwt.javac excludes="**/EmulatedCharset.java,**/HashCodes.java">
       <src path="super/com/google/gwt/emul/javaemul/internal"/>
       <classpath>
         <pathelement location="${gwt.tools.lib}/gss/2015-10-07/closure-stylesheets-library-20151007-rebased.jar"/>