diff --git a/core-api/src/main/java/com/optimizely/ab/event/BatchEventProcessor.java b/core-api/src/main/java/com/optimizely/ab/event/BatchEventProcessor.java
index c99d3bb52..201f6e8ee 100644
--- a/core-api/src/main/java/com/optimizely/ab/event/BatchEventProcessor.java
+++ b/core-api/src/main/java/com/optimizely/ab/event/BatchEventProcessor.java
@@ -313,6 +313,10 @@ public BatchEventProcessor build(boolean shouldStart) {
                 timeoutMillis = DEFAULT_TIMEOUT_INTERVAL;
             }
 
+            if (eventHandler == null) {
+                throw new IllegalArgumentException("EventHandler was not configured");
+            }
+
             if (executor == null) {
                 final ThreadFactory threadFactory = Executors.defaultThreadFactory();
                 executor = Executors.newSingleThreadExecutor(runnable -> {
diff --git a/core-api/src/test/java/com/optimizely/ab/event/BatchEventProcessorTest.java b/core-api/src/test/java/com/optimizely/ab/event/BatchEventProcessorTest.java
index b9d45fc88..8f8e94a8a 100644
--- a/core-api/src/test/java/com/optimizely/ab/event/BatchEventProcessorTest.java
+++ b/core-api/src/test/java/com/optimizely/ab/event/BatchEventProcessorTest.java
@@ -67,7 +67,9 @@ public void setUp() throws Exception {
 
     @After
     public void tearDown() throws Exception {
-        eventProcessor.close();
+        if (eventProcessor != null) {
+            eventProcessor.close();
+        }
     }
 
     @Test
@@ -288,6 +290,11 @@ public void testInvalidTimeoutUsesDefault() {
         assertEquals(eventProcessor.timeoutMillis, BatchEventProcessor.DEFAULT_TIMEOUT_INTERVAL);
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testDefaultEventHandler() {
+        eventProcessor = BatchEventProcessor.builder().build();
+    }
+
     private void setEventProcessor(EventHandler eventHandler) {
         eventProcessor = BatchEventProcessor.builder()
             .withEventQueue(eventQueue)
diff --git a/core-httpclient-impl/README.md b/core-httpclient-impl/README.md
index 4d7c32c14..0546a8f68 100644
--- a/core-httpclient-impl/README.md
+++ b/core-httpclient-impl/README.md
@@ -24,6 +24,8 @@ compile 'com.optimizely.ab:core-httpclient-impl:{VERSION}'
 
 ## Basic usage
 ```java
+package com.optimizely;
+
 import com.optimizely.ab.Optimizely;
 import com.optimizely.ab.OptimizelyFactory;
 
@@ -38,9 +40,13 @@ public class App {
 
 ## Advanced usage
 ```java
+package com.optimizely;
+
 import com.optimizely.ab.Optimizely;
+import com.optimizely.ab.config.ProjectConfigManager;
 import com.optimizely.ab.config.HttpProjectConfigManager;
 import com.optimizely.ab.event.AsyncEventHandler;
+import com.optimizely.ab.event.EventHandler;
 import java.util.concurrent.TimeUnit;
 
 public class App {
@@ -54,12 +60,12 @@ public class App {
 
         ProjectConfigManager projectConfigManager = HttpProjectConfigManager.builder()
             .withSdkKey(sdkKey)
-            .withPollingInterval(1, TimeUnit.MINUTES)
+            .withPollingInterval(1L, TimeUnit.MINUTES)
             .build();
 
         Optimizely optimizely = Optimizely.builder()
-            .withConfig(projectConfigManager)
             .withEventHandler(eventHandler)
+            .withConfigManager(projectConfigManager)
             .build();
     }
 }