diff --git a/wsclient/src/main/java/org/hpccsystems/ws/client/utils/Connection.java b/wsclient/src/main/java/org/hpccsystems/ws/client/utils/Connection.java
index a28da183d..6b831f177 100644
--- a/wsclient/src/main/java/org/hpccsystems/ws/client/utils/Connection.java
+++ b/wsclient/src/main/java/org/hpccsystems/ws/client/utils/Connection.java
@@ -287,7 +287,22 @@ public static boolean isSslProtocol(String protocol)
      */
     public Connection(String connectionstring) throws MalformedURLException
     {
-        URL theurl = new URL(connectionstring);
+        URL theurl = null;
+        try
+        {
+            theurl = new URL(connectionstring);
+        }
+        catch (MalformedURLException e)
+        {
+            if (connectionstring.contains("_"))
+            {
+                throw new MalformedURLException("Invalid URL: Check hostname for invalid underscores: '" + connectionstring + "': " + e.getMessage());
+            }
+            else
+            {
+                throw e;
+            }
+        }
 
         setProtocol(theurl.getProtocol());