diff --git a/CHANGES.txt b/CHANGES.txt
index c0c8ac70a29..8ccdaa5509c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -9,6 +9,7 @@ Release 0.19.0 - Unreleased
                (Izaak Rubin via Stack)
    HBASE-953   Enable BLOCKCACHE by default [WAS -> Reevaluate HBASE-288 block
                caching work....?] -- Update your hbad-default.xml file!
+   HBASE-636   java6 as a requirement
 
   BUG FIXES
    HBASE-891   HRS.validateValuesLength throws IOE, gets caught in the retries
diff --git a/build.xml b/build.xml
index 19a2d6195a9..391bc437547 100644
--- a/build.xml
+++ b/build.xml
@@ -64,13 +64,14 @@
 
   <property name="javac.deprecation" value="off"/>
   <property name="javac.debug" value="on"/>
+  <property name="javac.version" value="1.6"/>
 
   <property name="clover.db.dir" location="${build.dir}/test/clover/db"/>
   <property name="clover.report.dir" location="${build.dir}/test/clover/reports"/>
 
 
   <property name="javadoc.link.java"
-    value="http://java.sun.com/j2se/1.5/docs/api/"/>
+    value="http://java.sun.com/javase/6/docs/api/index.html"/>
   <property name="javadoc.packages" value="org.apache.hadoop.hbase.*"/>
   <property name="jarfile" value="${build.dir}/${final.name}.jar" />
 
@@ -146,6 +147,8 @@
     includes="**/*.java"
     destdir="${build.classes}"
     debug="${javac.debug}"
+     target="${javac.version}"
+     source="${javac.version}"
     deprecation="${javac.deprecation}">
      <classpath refid="classpath"/>
    </javac>
@@ -397,6 +400,8 @@
        includes="**/*.java" 
        destdir="${build.test}" 
        debug="${javac.debug}"
+       target="${javac.version}"
+       source="${javac.version}"
        deprecation="${javac.deprecation}"> 
     <classpath refid="test.classpath"/> 
     </javac>