diff --git a/service/src/java/org/apache/hive/service/cli/operation/ExecuteStatementOperation.java b/service/src/java/org/apache/hive/service/cli/operation/ExecuteStatementOperation.java
index 6444944..d256364 100644
--- a/service/src/java/org/apache/hive/service/cli/operation/ExecuteStatementOperation.java
+++ b/service/src/java/org/apache/hive/service/cli/operation/ExecuteStatementOperation.java
@@ -75,7 +75,7 @@ public abstract class ExecuteStatementOperation extends Operation {
       newExecOP = new SQLOperation(parentSession, statement, confOverlay);
       // check if this is needs to be run asynchronously
       boolean isAsyncOP = (parentSession.getHiveConf().getBoolVar(ConfVars.HIVE_SERVER2_BLOCKING_QUERY) == false);
-      if(confOverlay.containsKey(ConfVars.HIVE_SERVER2_BLOCKING_QUERY.toString())) {
+      if ((confOverlay != null)  && confOverlay.containsKey(ConfVars.HIVE_SERVER2_BLOCKING_QUERY.toString())) {
         isAsyncOP = confOverlay.get(ConfVars.HIVE_SERVER2_BLOCKING_QUERY.toString()).equalsIgnoreCase("false");
       }
       if (isAsyncOP) {
diff --git a/service/src/test/org/apache/hive/service/cli/CLIServiceTest.java b/service/src/test/org/apache/hive/service/cli/CLIServiceTest.java
index 6a18629..840e763 100644
--- a/service/src/test/org/apache/hive/service/cli/CLIServiceTest.java
+++ b/service/src/test/org/apache/hive/service/cli/CLIServiceTest.java
@@ -129,6 +129,20 @@ public abstract class CLIServiceTest {
   }
 
   /**
+   * Test that execute doesn't fail when confOverlay is null
+   * @throws Exception
+   */
+  @Test
+  public void testNullConfOverlay() throws Exception {
+    SessionHandle sessionHandle = client.openSession("tom", "password", new HashMap<String, String>());
+    assertNotNull(sessionHandle);
+    String statement = "show databases";
+    OperationHandle opHandle = client.executeStatement(sessionHandle, statement, null);
+    client.closeOperation(opHandle);
+    client.closeSession(sessionHandle);
+  }
+
+  /**
    * Test per statement configuration overlay
    * @throws Exception
    */