AVRO-1807: Java/JSON: Throw for unsupported objects rather than ignoring.
diff --git a/CHANGES.txt b/CHANGES.txt
index bccaf17..f5284c8 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -42,6 +42,8 @@
 
     AVRO-1841: Add clientside githooks to do basic commit validation (nielsbasjes) 
 
+    AVRO-1807: Java/JSON: Throw for unsupported objects rather than ignoring. (blue)
+
   BUG FIXES
 
     AVRO-1493. Java: Avoid the "Turkish Locale Problem". Schema fingerprints are
diff --git a/lang/java/avro/src/main/java/org/apache/avro/util/internal/JacksonUtils.java b/lang/java/avro/src/main/java/org/apache/avro/util/internal/JacksonUtils.java
index 8d5661b..ca98e4c 100644
--- a/lang/java/avro/src/main/java/org/apache/avro/util/internal/JacksonUtils.java
+++ b/lang/java/avro/src/main/java/org/apache/avro/util/internal/JacksonUtils.java
@@ -83,6 +83,8 @@
       generator.writeNumber((Integer) datum);
     } else if (datum instanceof Boolean) { // boolean
       generator.writeBoolean((Boolean) datum);
+    } else {
+      throw new AvroRuntimeException("Unknown datum class: " + datum.getClass());
     }
   }