diff --git a/src/main/java/hudson/plugins/ec2/AmazonEC2Cloud.java b/src/main/java/hudson/plugins/ec2/AmazonEC2Cloud.java
index 5d990f2d8..cad58d077 100644
--- a/src/main/java/hudson/plugins/ec2/AmazonEC2Cloud.java
+++ b/src/main/java/hudson/plugins/ec2/AmazonEC2Cloud.java
@@ -38,6 +38,8 @@
 import java.net.URL;
 import java.util.List;
 import java.util.Locale;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.servlet.ServletException;
 
@@ -59,6 +61,8 @@
  * @author Kohsuke Kawaguchi
  */
 public class AmazonEC2Cloud extends EC2Cloud {
+    private final static Logger LOGGER = Logger.getLogger(AmazonEC2Cloud.class.getName());
+    
     /**
      * Represents the region. Can be null for backward compatibility reasons.
      */
@@ -178,6 +182,17 @@ public FormValidation doCheckCloudName(@QueryParameter String value) {
             return FormValidation.ok();
         }
 
+        public FormValidation doCheckAltEC2Endpoint(@QueryParameter String value) {
+            if (Util.fixEmpty(value) != null) {
+                try {
+                    new URL(value);
+                } catch (MalformedURLException ignored) {
+                    return FormValidation.error(Messages.AmazonEC2Cloud_MalformedUrl());
+                }
+            }
+            return FormValidation.ok();
+        }
+        
         @RequirePOST
         public ListBoxModel doFillRegionItems(
                 @QueryParameter String altEC2Endpoint,
@@ -212,8 +227,12 @@ URL determineEC2EndpointURL(@Nullable String altEC2Endpoint) throws MalformedURL
             if (Util.fixEmpty(altEC2Endpoint) == null) {
                 return new URL(DEFAULT_EC2_ENDPOINT);
             }
-
-            return new URL(altEC2Endpoint);
+            try {
+                return new URL(altEC2Endpoint);    
+            } catch (MalformedURLException e) {
+                LOGGER.log(Level.WARNING, "The alternate EC2 endpoint is malformed ({0}). Using the default endpoint ({1})", new Object[]{altEC2Endpoint, DEFAULT_EC2_ENDPOINT});
+                return new URL(DEFAULT_EC2_ENDPOINT);
+            }
         }
 
         @RequirePOST
diff --git a/src/main/resources/hudson/plugins/ec2/Messages.properties b/src/main/resources/hudson/plugins/ec2/Messages.properties
index c17b48acb..0152a90c3 100644
--- a/src/main/resources/hudson/plugins/ec2/Messages.properties
+++ b/src/main/resources/hudson/plugins/ec2/Messages.properties
@@ -9,5 +9,5 @@ EC2SpotSlave.Spot1=Spot $
 EC2SpotSlave.Spot2= max bid price
 
 AmazonEC2Cloud.NonUniqName=Cloud name must be unique across EC2 clouds
-
+AmazonEC2Cloud.MalformedUrl=The URL is malformed. The default endpoint will be used
 General.MissingPermission=You do not have the Overall/Administer right to modify this field