diff --git a/undertow/src/main/java/org/wildfly/extension/undertow/filters/ModClusterServiceConfigurator.java b/undertow/src/main/java/org/wildfly/extension/undertow/filters/ModClusterServiceConfigurator.java
index 8b8ad402c853..7af81b0c9b48 100644
--- a/undertow/src/main/java/org/wildfly/extension/undertow/filters/ModClusterServiceConfigurator.java
+++ b/undertow/src/main/java/org/wildfly/extension/undertow/filters/ModClusterServiceConfigurator.java
@@ -10,6 +10,7 @@
 import java.io.IOException;
 import java.net.InetAddress;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -161,8 +162,8 @@ public ServiceBuilder<?> build(ServiceTarget target) {
         Consumer<Map.Entry<ModCluster, MCMPConfig>> consumer = new Consumer<>() {
             @Override
             public void accept(Map.Entry<ModCluster, MCMPConfig> entry) {
-                service.accept(entry.getKey());
-                config.accept(entry.getValue());
+                service.accept(Optional.ofNullable(entry).map(Map.Entry::getKey).orElse(null));
+                config.accept(Optional.ofNullable(entry).map(Map.Entry::getValue).orElse(null));
             }
         };
         return builder.setInstance(new FunctionalService<>(consumer, Function.identity(), this, this));