diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index bb34392b669..709ec703b79 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -366,6 +366,9 @@ Release 2.0.4-beta - UNRELEASED
 
     HADOOP-9297. remove old record IO generation and tests. (tucu)
 
+    HADOOP-9154. SortedMapWritable#putAll() doesn't add key/value classes to
+    the map. (Karthik Kambatla via tomwhite)
+
 Release 2.0.3-alpha - 2013-02-06 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/AbstractMapWritable.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/AbstractMapWritable.java
index 6bd9efc689e..54903394feb 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/AbstractMapWritable.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/AbstractMapWritable.java
@@ -29,6 +29,8 @@ import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 
+import com.google.common.annotations.VisibleForTesting;
+
 /**
  * Abstract base class for MapWritable and SortedMapWritable
  * 
@@ -45,10 +47,12 @@ public abstract class AbstractMapWritable implements Writable, Configurable {
   private AtomicReference<Configuration> conf;
   
   /* Class to id mappings */
-  private Map<Class, Byte> classToIdMap = new ConcurrentHashMap<Class, Byte>();
+  @VisibleForTesting
+  Map<Class, Byte> classToIdMap = new ConcurrentHashMap<Class, Byte>();
   
   /* Id to Class mappings */
-  private Map<Byte, Class> idToClassMap = new ConcurrentHashMap<Byte, Class>();
+  @VisibleForTesting
+  Map<Byte, Class> idToClassMap = new ConcurrentHashMap<Byte, Class>();
   
   /* The number of new classes (those not established by the constructor) */
   private volatile byte newClasses = 0;
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/SortedMapWritable.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/SortedMapWritable.java
index c80af15c9e2..3b51fc25ffc 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/SortedMapWritable.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/SortedMapWritable.java
@@ -141,7 +141,7 @@ public class SortedMapWritable extends AbstractMapWritable
     for (Map.Entry<? extends WritableComparable, ? extends Writable> e:
       t.entrySet()) {
       
-      instance.put(e.getKey(), e.getValue());
+      put(e.getKey(), e.getValue());
     }
   }
 
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestSortedMapWritable.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestSortedMapWritable.java
index 1fbfcad7627..5ed1db25ffb 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestSortedMapWritable.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/TestSortedMapWritable.java
@@ -164,4 +164,18 @@ public class TestSortedMapWritable {
     assertTrue(failureReason, !mapA.equals(mapB));
     assertTrue(failureReason, !mapB.equals(mapA));
   }
+
+  @Test(timeout = 1000)
+  public void testPutAll() {
+    SortedMapWritable map1 = new SortedMapWritable();
+    SortedMapWritable map2 = new SortedMapWritable();
+    map1.put(new Text("key"), new Text("value"));
+    map2.putAll(map1);
+
+    assertEquals("map1 entries don't match map2 entries", map1, map2);
+    assertTrue(
+        "map2 doesn't have class information from map1",
+        map2.classToIdMap.containsKey(Text.class)
+            && map2.idToClassMap.containsValue(Text.class));
+  }
 }