diff --git a/src/main/java/org/elasticsearch/common/xcontent/XContentBuilder.java b/src/main/java/org/elasticsearch/common/xcontent/XContentBuilder.java
index 6146dfdb4b9..ee0b742ca46 100644
--- a/src/main/java/org/elasticsearch/common/xcontent/XContentBuilder.java
+++ b/src/main/java/org/elasticsearch/common/xcontent/XContentBuilder.java
@@ -529,7 +529,7 @@ public final class XContentBuilder implements BytesStream {
         return this;
     }
 
-    public XContentBuilder field(XContentBuilderString name, BytesRef value) throws IOException {
+    public XContentBuilder utf8Field(XContentBuilderString name, BytesRef value) throws IOException {
         field(name);
         generator.writeUTF8String(value.bytes, value.offset, value.length);
         return this;
@@ -1135,6 +1135,8 @@ public final class XContentBuilder implements BytesStream {
             generator.writeNumber(((Float) value).floatValue());
         } else if (type == Double.class) {
             generator.writeNumber(((Double) value).doubleValue());
+        } else if (type == Byte.class) {
+            generator.writeNumber(((Byte)value).byteValue());
         } else if (type == Short.class) {
             generator.writeNumber(((Short) value).shortValue());
         } else if (type == Boolean.class) {
diff --git a/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java b/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
index f99b15ba5a6..619c904b751 100644
--- a/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
+++ b/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
@@ -144,7 +144,7 @@ public class SignificantStringTerms extends InternalSignificantTerms {
             // and I end up with buckets that contravene the user's min_doc_count criteria in my reducer
             if (bucket.subsetDf >= minDocCount) {
                 builder.startObject();
-                builder.field(CommonFields.KEY, ((Bucket) bucket).termBytes);
+                builder.utf8Field(CommonFields.KEY, ((Bucket) bucket).termBytes);
                 builder.field(CommonFields.DOC_COUNT, bucket.getDocCount());
                 builder.field("score", bucket.score);
                 builder.field("bg_count", bucket.supersetDf);
diff --git a/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTerms.java b/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTerms.java
index 50378fe86fe..33db4e89664 100644
--- a/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTerms.java
+++ b/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTerms.java
@@ -132,7 +132,7 @@ public class StringTerms extends InternalTerms {
         builder.startArray(CommonFields.BUCKETS);
         for (InternalTerms.Bucket bucket : buckets) {
             builder.startObject();
-            builder.field(CommonFields.KEY, ((Bucket) bucket).termBytes);
+            builder.utf8Field(CommonFields.KEY, ((Bucket) bucket).termBytes);
             builder.field(CommonFields.DOC_COUNT, bucket.getDocCount());
             ((InternalAggregations) bucket.getAggregations()).toXContentInternal(builder, params);
             builder.endObject();
diff --git a/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java b/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
index d37ef0dc4c7..fc00f931d7a 100644
--- a/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
+++ b/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
@@ -172,6 +172,13 @@ public class XContentBuilderTests extends ElasticsearchTestCase {
         assertThat(builder.string(), equalTo("{\"test_name\":\"value\"}"));
     }
 
+    @Test
+    public void testByteConversion() throws Exception {
+        XContentBuilder builder = XContentFactory.contentBuilder(XContentType.JSON);
+        builder.startObject().field("test_name", (Byte)(byte)120).endObject();
+        assertThat(builder.bytes().toUtf8(), equalTo("{\"test_name\":120}"));
+    }
+
     @Test
     public void testDateTypesConversion() throws Exception {
         Date date = new Date();
@@ -253,4 +260,4 @@ public class XContentBuilderTests extends ElasticsearchTestCase {
 
         assertThat(i, equalTo(terms.size()));
     }
-}
\ No newline at end of file
+}