diff --git a/indexing-service/src/main/java/io/druid/indexing/common/task/HadoopIndexTask.java b/indexing-service/src/main/java/io/druid/indexing/common/task/HadoopIndexTask.java
index 730a4a8f7aafe9246181103f08f0bdb0da5d660d..e687875433b3904794d3b084579a3eba14212c6b 100644
--- a/indexing-service/src/main/java/io/druid/indexing/common/task/HadoopIndexTask.java
+++ b/indexing-service/src/main/java/io/druid/indexing/common/task/HadoopIndexTask.java
@@ -23,7 +23,7 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.type.TypeReference;
-import com.google.api.client.util.Sets;
+import com.google.api.client.util.Lists;
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
@@ -50,7 +50,6 @@ import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Set;
 
 public class HadoopIndexTask extends AbstractTask
 {
@@ -131,7 +130,7 @@ public class HadoopIndexTask extends AbstractTask
         aetherClient, hadoopCoordinates
     );
 
-    final Set<URL> extensionURLs = Sets.newHashSet();
+    final List<URL> extensionURLs = Lists.newArrayList();
     for (String coordinate : extensionsConfig.getCoordinates()) {
       final ClassLoader coordinateLoader = Initialization.getClassLoaderForCoordinates(
           aetherClient, coordinate
@@ -139,17 +138,18 @@ public class HadoopIndexTask extends AbstractTask
       extensionURLs.addAll(Arrays.asList(((URLClassLoader) coordinateLoader).getURLs()));
     }
 
-    final Set<URL> nonHadoopURLs = Sets.newHashSet();
+    final List<URL> nonHadoopURLs = Lists.newArrayList();
     nonHadoopURLs.addAll(Arrays.asList(((URLClassLoader) HadoopIndexTask.class.getClassLoader()).getURLs()));
 
-    final Set<URL> driverURLs = Sets.newHashSet();
+    final List<URL> driverURLs = Lists.newArrayList();
     driverURLs.addAll(nonHadoopURLs);
+    // put hadoop dependencies last to avoid jets3t & apache.httpcore version conflicts
     driverURLs.addAll(Arrays.asList(((URLClassLoader) hadoopLoader).getURLs()));
 
     final URLClassLoader loader = new URLClassLoader(driverURLs.toArray(new URL[driverURLs.size()]), null);
     Thread.currentThread().setContextClassLoader(loader);
 
-    final Set<URL> jobUrls = Sets.newHashSet();
+    final List<URL> jobUrls = Lists.newArrayList();
     jobUrls.addAll(nonHadoopURLs);
     jobUrls.addAll(extensionURLs);
 
diff --git a/services/src/main/java/io/druid/cli/CliHadoopIndexer.java b/services/src/main/java/io/druid/cli/CliHadoopIndexer.java
index fed08b5d1b3c98f21378e8ad5714b9f14aa07b2e..208b8a97e8318d347d907c75e50c590e22ea5071 100644
--- a/services/src/main/java/io/druid/cli/CliHadoopIndexer.java
+++ b/services/src/main/java/io/druid/cli/CliHadoopIndexer.java
@@ -19,7 +19,6 @@
 
 package io.druid.cli;
 
-import com.google.api.client.util.Sets;
 import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
 import com.google.inject.Inject;
@@ -37,7 +36,6 @@ import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Set;
 
 /**
  */
@@ -69,7 +67,7 @@ public class CliHadoopIndexer implements Runnable
           aetherClient, hadoopCoordinates
       );
 
-      final Set<URL> extensionURLs = Sets.newHashSet();
+      final List<URL> extensionURLs = Lists.newArrayList();
       for (String coordinate : extensionsConfig.getCoordinates()) {
         final ClassLoader coordinateLoader = Initialization.getClassLoaderForCoordinates(
             aetherClient, coordinate
@@ -77,17 +75,18 @@ public class CliHadoopIndexer implements Runnable
         extensionURLs.addAll(Arrays.asList(((URLClassLoader) coordinateLoader).getURLs()));
       }
 
-      final Set<URL> nonHadoopURLs = Sets.newHashSet();
+      final List<URL> nonHadoopURLs = Lists.newArrayList();
       nonHadoopURLs.addAll(Arrays.asList(((URLClassLoader) CliHadoopIndexer.class.getClassLoader()).getURLs()));
 
-      final Set<URL> driverURLs = Sets.newHashSet();
+      final List<URL> driverURLs = Lists.newArrayList();
       driverURLs.addAll(nonHadoopURLs);
+      // put hadoop dependencies last to avoid jets3t & apache.httpcore version conflicts
       driverURLs.addAll(Arrays.asList(((URLClassLoader) hadoopLoader).getURLs()));
 
       final URLClassLoader loader = new URLClassLoader(driverURLs.toArray(new URL[driverURLs.size()]), null);
       Thread.currentThread().setContextClassLoader(loader);
 
-      final Set<URL> jobUrls = Sets.newHashSet();
+      final List<URL> jobUrls = Lists.newArrayList();
       jobUrls.addAll(nonHadoopURLs);
       jobUrls.addAll(extensionURLs);