diff --git a/gson/GSON 2.0 NOTES.txt b/gson/GSON 2.0 NOTES.txt
index 1896c8ec..7f8e843f 100644
--- a/gson/GSON 2.0 NOTES.txt	
+++ b/gson/GSON 2.0 NOTES.txt	
@@ -66,4 +66,15 @@ GSON 1.x creates the empty string "" if the only element is skipped
 GSON 2.x writes "null" if the only element is skipped
 com.google.gson.functional.ObjectTest.testAnonymousLocalClassesSerialization
 com.google.gson.functional.FieldExclusionTest.testInnerClassExclusion
-com.google.gson.functional.VersioningTest.testIgnoreLaterVersionClassSerialization
\ No newline at end of file
+com.google.gson.functional.VersioningTest.testIgnoreLaterVersionClassSerialization
+
+
+GSON 1.x permits duplicate map keys.
+GSON 2.x rejects duplicate map keys.
+com.google.gson.functional.MapTest.testMapDeserializationWithDuplicateKeys
+
+
+GSON 1.x doesn't serialize subclass fields in collections
+GSON 2.x does serialize subclass fields in collections
+com.google.gson.functional.InheritanceTest.testClassWithBaseCollectionFieldSerialization
+com.google.gson.functional.MoreSpecificTypeSerializationTest.testListOfSubclassFields
\ No newline at end of file
diff --git a/gson/src/test/java/com/google/gson/functional/MapTest.java b/gson/src/test/java/com/google/gson/functional/MapTest.java
index 071e1c4d..530bc9bd 100755
--- a/gson/src/test/java/com/google/gson/functional/MapTest.java
+++ b/gson/src/test/java/com/google/gson/functional/MapTest.java
@@ -25,6 +25,7 @@ import com.google.gson.JsonParseException;
 import com.google.gson.JsonPrimitive;
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
+import com.google.gson.JsonSyntaxException;
 import com.google.gson.common.TestTypes;
 import com.google.gson.internal.$Gson$Types;
 import com.google.gson.reflect.TypeToken;
@@ -424,8 +425,8 @@ public class MapTest extends TestCase {
   public void testGeneralMapField() throws Exception {
     MapWithGeneralMapParameters map = new MapWithGeneralMapParameters();
     map.map.put("string", "testString");
-    map.map.put("stringArray", new String[] { "one", "two" });
-    map.map.put("objectArray", new Object[] { 1, 2L, "three" });
+    map.map.put("stringArray", new String[]{"one", "two"});
+    map.map.put("objectArray", new Object[]{1, 2L, "three"});
 
     String expected = "{\"map\":{\"string\":\"testString\",\"stringArray\":"
         + "[\"one\",\"two\"],\"objectArray\":[1,2,\"three\"]}}";
@@ -479,6 +480,14 @@ public class MapTest extends TestCase {
     assertEquals(map, gson.fromJson(json, new TypeToken<Map<Boolean, String>>() {}.getType()));
   }
 
+  public void testMapDeserializationWithDuplicateKeys() {
+    try {
+      gson.fromJson("{'a':1,'a':2}", new TypeToken<Map<String, Integer>>() {}.getType());
+      fail();
+    } catch (JsonSyntaxException expected) {
+    }
+  }
+
   static class Point {
     private final int x;
     private final int y;