diff --git a/smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java b/smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java
index f8e69533c..544f3ac48 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/ConnectionConfiguration.java
@@ -20,6 +20,7 @@ package org.jivesoftware.smack;
 import org.jivesoftware.smack.packet.Session;
 import org.jivesoftware.smack.proxy.ProxyInfo;
 import org.jivesoftware.smack.util.DNSUtil;
+import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smack.util.dns.HostAddress;
 
 import javax.net.SocketFactory;
@@ -180,6 +181,9 @@ public class ConnectionConfiguration implements Cloneable {
     }
 
     protected void init(String serviceName, ProxyInfo proxy) {
+        if (StringUtils.isEmpty(serviceName)) {
+            throw new IllegalArgumentException("serviceName must not be the empty String");
+        }
         this.serviceName = serviceName;
         this.proxy = proxy;
 
@@ -597,6 +601,9 @@ public class ConnectionConfiguration implements Cloneable {
     }
 
     private void initHostAddresses(String host, int port) {
+        if (StringUtils.isEmpty(host)) {
+            throw new IllegalArgumentException("host must not be the empty String");
+        }
         hostAddresses = new ArrayList<HostAddress>(1);
         HostAddress hostAddress;
         hostAddress = new HostAddress(host, port);
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/util/StringUtils.java b/smack-core/src/main/java/org/jivesoftware/smack/util/StringUtils.java
index 132e1d340..796b7ff1f 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/util/StringUtils.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/util/StringUtils.java
@@ -528,12 +528,22 @@ public class StringUtils {
     }
 
     /**
-     * Returns true if the given CharSequence is not null or empty.
+     * Returns true if the given CharSequence is null or empty.
      *
      * @param cs
-     * @return true if the given CharSequence is not null or empty
+     * @return true if the given CharSequence is null or empty
      */
     public static boolean isNullOrEmpty(CharSequence cs) {
-        return cs == null || cs.length() == 0;
+        return cs == null || isEmpty(cs);
+    }
+
+    /**
+     * Returns true if the given CharSequence is empty
+     * 
+     * @param cs
+     * @return true if the given CharSequence is empty
+     */
+    public static boolean isEmpty(CharSequence cs) {
+        return cs.length() == 0;
     }
 }