diff --git a/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/MessageSource.java b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/MessageSource.java
new file mode 100644
index 00000000..b8e51109
--- /dev/null
+++ b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/MessageSource.java
@@ -0,0 +1,6 @@
+package org.ops4j.pax.cdi.sample6;
+
+
+public interface MessageSource extends MessageProducer {
+
+}
diff --git a/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/AlternativeMessageSourceImpl.java b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/AlternativeMessageSourceImpl.java
new file mode 100644
index 00000000..a36542c6
--- /dev/null
+++ b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/AlternativeMessageSourceImpl.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015 Harald Wellmann.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.ops4j.pax.cdi.sample6.impl;
+
+import javax.enterprise.inject.Alternative;
+
+import org.ops4j.pax.cdi.sample6.MessageSource;
+
+@Alternative
+public class AlternativeMessageSourceImpl implements MessageSource {
+
+    @Override
+    public String getMessage() {
+        return "Quod erat demonstrandum.";
+    }
+}
diff --git a/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageProducerImpl.java b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageProducerImpl.java
index dd157f33..4fa0cf87 100644
--- a/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageProducerImpl.java
+++ b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageProducerImpl.java
@@ -17,14 +17,20 @@
  */
 package org.ops4j.pax.cdi.sample6.impl;
 
+import javax.inject.Inject;
+
 import org.ops4j.pax.cdi.api.OsgiServiceProvider;
 import org.ops4j.pax.cdi.sample6.MessageProducer;
+import org.ops4j.pax.cdi.sample6.MessageSource;
 
 @OsgiServiceProvider
 public class MessageProducerImpl implements MessageProducer {
 
+    @Inject
+    private MessageSource source;
+
     @Override
     public String getMessage() {
-        return "Quod erat demonstrandum.";
+        return source.getMessage();
     }
 }
diff --git a/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageSourceImpl.java b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageSourceImpl.java
new file mode 100644
index 00000000..7c8b8816
--- /dev/null
+++ b/pax-cdi-samples/pax-cdi-sample6/src/main/java/org/ops4j/pax/cdi/sample6/impl/MessageSourceImpl.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2015 Harald Wellmann.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.ops4j.pax.cdi.sample6.impl;
+
+import org.ops4j.pax.cdi.sample6.MessageSource;
+
+
+public class MessageSourceImpl implements MessageSource {
+
+    @Override
+    public String getMessage() {
+        return "Tertium non datur.";
+    }
+}
diff --git a/pax-cdi-samples/pax-cdi-sample6/src/main/resources/META-INF/beans.xml b/pax-cdi-samples/pax-cdi-sample6/src/main/resources/META-INF/beans.xml
index e69de29b..53d88167 100644
--- a/pax-cdi-samples/pax-cdi-sample6/src/main/resources/META-INF/beans.xml
+++ b/pax-cdi-samples/pax-cdi-sample6/src/main/resources/META-INF/beans.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<beans xmlns="http://java.sun.com/xml/ns/javaee"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://jboss.org/schema/cdi/beans_1_0.xsd">
+    <alternatives>
+        <class>org.ops4j.pax.cdi.sample6.impl.AlternativeMessageSourceImpl</class>
+    </alternatives> 
+</beans>
diff --git a/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanBundleFilter.java b/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanBundleFilter.java
index 22633b58..5dac22b3 100644
--- a/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanBundleFilter.java
+++ b/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanBundleFilter.java
@@ -18,8 +18,10 @@
 package org.ops4j.pax.cdi.spi.scan;
 
 import java.net.URL;
+import java.util.ArrayList;
 import java.util.Dictionary;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.ops4j.pax.cdi.spi.BeanBundles;
@@ -45,8 +47,9 @@ public boolean accept(Bundle providerBundle, String className) {
                 return true;
             case NONE:
                 return false;
+            default:
+                throw new IllegalArgumentException(descriptor.getBeanDiscoveryMode().toString());
         }
-        return false;
     }
 
     public BeanDescriptor findDescriptor(Bundle providerBundle) {
@@ -85,4 +88,12 @@ private boolean isWebBundle(Bundle bundle) {
         String contextPath = headers.get("Web-ContextPath");
         return (contextPath != null);
     }
+
+    public List<URL> getBeanDescriptors() {
+        List<URL> urls = new ArrayList<>();
+        for (BeanDescriptor descriptor : descriptorMap.values()) {
+            urls.add(descriptor.getUrl());
+        }
+        return urls;
+    }
 }
diff --git a/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanScanner.java b/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanScanner.java
index 2276b16b..f28676f8 100644
--- a/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanScanner.java
+++ b/pax-cdi-spi/src/main/java/org/ops4j/pax/cdi/spi/scan/BeanScanner.java
@@ -94,8 +94,8 @@ public Set<String> getBeanClasses() {
      * @return unmodifiable set
      */
     public Set<URL> getBeanDescriptors() {
-        // FIXME
-        return Collections.emptySet();
+        Set<URL> urls = new HashSet<>(filter.getBeanDescriptors());
+        return Collections.unmodifiableSet(urls);
     }
 
     /**