Index: pom.xml
===================================================================
--- pom.xml	(revision 1709780)
+++ pom.xml	(working copy)
@@ -44,7 +44,7 @@
         <dependency>
             <groupId>com.amazonaws</groupId>
             <artifactId>aws-java-sdk-s3</artifactId>
-            <version>1.9.22</version>
+            <version>1.10.27</version>
         </dependency>
         <dependency>
             <groupId>org.apache.jackrabbit</groupId>
Index: src/main/java/org/apache/jackrabbit/aws/ext/ds/S3Backend.java
===================================================================
--- src/main/java/org/apache/jackrabbit/aws/ext/ds/S3Backend.java	(revision 1709780)
+++ src/main/java/org/apache/jackrabbit/aws/ext/ds/S3Backend.java	(working copy)
@@ -52,6 +52,7 @@
 import com.amazonaws.AmazonServiceException;
 import com.amazonaws.event.ProgressEvent;
 import com.amazonaws.event.ProgressListener;
+import com.amazonaws.regions.Regions;
 import com.amazonaws.services.s3.AmazonS3Client;
 import com.amazonaws.services.s3.model.CopyObjectRequest;
 import com.amazonaws.services.s3.model.DeleteObjectsRequest;
@@ -65,6 +66,7 @@
 import com.amazonaws.services.s3.transfer.Copy;
 import com.amazonaws.services.s3.transfer.TransferManager;
 import com.amazonaws.services.s3.transfer.Upload;
+import com.amazonaws.util.StringUtils;
 
 /**
  * A data store backend that stores data on Amazon S3.
@@ -139,12 +141,24 @@
             }
             String region = prop.getProperty(S3Constants.S3_REGION);
             Region s3Region = null;
-            if (Utils.DEFAULT_AWS_BUCKET_REGION.equals(region)) {
-                s3Region =  Region.US_Standard;
-            } else if (Region.EU_Ireland.toString().equals(region)) {
-                s3Region = Region.EU_Ireland;
+            if (StringUtils.isNullOrEmpty(region)) {
+                com.amazonaws.regions.Region ec2Region = Regions.getCurrentRegion();
+                if (ec2Region != null) {
+                    s3Region = Region.fromValue(ec2Region.getName());
+                } else {
+                    throw new AmazonClientException(
+                        "parameter ["
+                            + S3Constants.S3_REGION
+                            + "] not configured and cannot be derived from environment");
+                }
             } else {
-                s3Region = Region.fromValue(region);
+                if (Utils.DEFAULT_AWS_BUCKET_REGION.equals(region)) {
+                    s3Region = Region.US_Standard;
+                } else if (Region.EU_Ireland.toString().equals(region)) {
+                    s3Region = Region.EU_Ireland;
+                } else {
+                    s3Region = Region.fromValue(region);
+                }
             }
             
             if (!s3service.doesBucketExist(bucket)) {
Index: src/main/java/org/apache/jackrabbit/aws/ext/Utils.java
===================================================================
--- src/main/java/org/apache/jackrabbit/aws/ext/Utils.java	(revision 1709780)
+++ src/main/java/org/apache/jackrabbit/aws/ext/Utils.java	(working copy)
@@ -26,14 +26,16 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.amazonaws.AmazonClientException;
 import com.amazonaws.ClientConfiguration;
 import com.amazonaws.Protocol;
 import com.amazonaws.auth.AWSCredentials;
 import com.amazonaws.auth.BasicAWSCredentials;
-import com.amazonaws.services.s3.model.Region;
+import com.amazonaws.regions.Regions;
 import com.amazonaws.services.s3.AmazonS3;
 import com.amazonaws.services.s3.AmazonS3Client;
 import com.amazonaws.services.s3.model.ObjectListing;
+import com.amazonaws.services.s3.model.Region;
 import com.amazonaws.services.s3.model.S3ObjectSummary;
 import com.amazonaws.util.StringUtils;
 
@@ -97,7 +99,16 @@
         String propEndPoint = prop.getProperty(S3Constants.S3_END_POINT);
         if ((propEndPoint != null) & !"".equals(propEndPoint)) {
             endpoint = propEndPoint;
-        } else {
+        } else { 
+            if (StringUtils.isNullOrEmpty(region)) {
+                com.amazonaws.regions.Region s3Region = Regions.getCurrentRegion();
+                if (s3Region != null) {
+                    region = s3Region.getName();
+                } else {
+                    throw new AmazonClientException("parameter ["
+                        + S3Constants.S3_REGION + "] not configured");
+                }
+            }
             if (DEFAULT_AWS_BUCKET_REGION.equals(region)) {
                 endpoint = S3 + DOT + AWSDOTCOM;
             } else if (Region.EU_Ireland.toString().equals(region)) {