diff --git a/smack-core/src/main/java/org/jivesoftware/smack/packet/Stanza.java b/smack-core/src/main/java/org/jivesoftware/smack/packet/Stanza.java
index b7226a965..4e341b023 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/packet/Stanza.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/packet/Stanza.java
@@ -119,6 +119,9 @@ public abstract class Stanza implements TopLevelStreamElement, Packet {
      * @param id the unique ID for the packet.
      */
     public void setStanzaId(String id) {
+        if (id != null) {
+            requireNotNullOrEmpty(id, "id must either be null or not the empty String");
+        }
         this.id = id;
     }
 
@@ -132,6 +135,18 @@ public abstract class Stanza implements TopLevelStreamElement, Packet {
         setStanzaId(packetID);
     }
 
+    /**
+     * Check if this stanza has an ID set.
+     *
+     * @return true if the stanza ID is set, false otherwise.
+     * @since 4.1
+     */
+    public boolean hasStanzaIdSet() {
+        // setStanzaId ensures that the id is either null or not empty,
+        // so we can assume that it is set if it's not null.
+        return id != null;
+    }
+
     /**
      * Returns who the packet is being sent "to", or <tt>null</tt> if
      * the value is not set. The XMPP protocol often makes the "to"