Index: core/src/main/scala/kafka/producer/Producer.scala
===================================================================
--- core/src/main/scala/kafka/producer/Producer.scala	(revision 1294302)
+++ core/src/main/scala/kafka/producer/Producer.scala	(working copy)
@@ -33,10 +33,6 @@
                                                           /* use the other constructor*/
 extends Logging {
   private val hasShutdown = new AtomicBoolean(false)
-  if(!Utils.propertyExists(config.zkConnect) && !Utils.propertyExists(config.brokerList))
-    throw new InvalidConfigException("At least one of zk.connect or broker.list must be specified")
-  if (Utils.propertyExists(config.zkConnect) && Utils.propertyExists(config.brokerList))
-    warn("Both zk.connect and broker.list provided (zk.connect takes precedence).")
   private val random = new java.util.Random
   // check if zookeeper based auto partition discovery is enabled
   private val zkEnabled = Utils.propertyExists(config.zkConnect)
Index: core/src/main/scala/kafka/producer/ProducerConfig.scala
===================================================================
--- core/src/main/scala/kafka/producer/ProducerConfig.scala	(revision 1294302)
+++ core/src/main/scala/kafka/producer/ProducerConfig.scala	(working copy)
@@ -33,9 +33,12 @@
     throw new InvalidConfigException("partitioner.class cannot be used when broker.list is set")
 
   /** If both broker.list and zk.connect options are specified, throw an exception */
-  if(brokerList != null && zkConnect != null)
+  if(propertyExists(brokerList) && propertyExists(zkConnect))
     throw new InvalidConfigException("only one of broker.list and zk.connect can be specified")
 
+  if(!propertyExists(config.zkConnect) && !propertyExists(config.brokerList))
+    throw new InvalidConfigException("At least one of zk.connect or broker.list must be specified")
+
   /** the partitioner class for partitioning events amongst sub-topics */
   val partitionerClass = Utils.getString(props, "partitioner.class", "kafka.producer.DefaultPartitioner")