Index: src/main/java/org/apache/maven/artifact/Artifact.java
===================================================================
--- src/main/java/org/apache/maven/artifact/Artifact.java	(revision 348837)
+++ src/main/java/org/apache/maven/artifact/Artifact.java	(working copy)
@@ -156,6 +156,8 @@
     void setAvailableVersions( List versions );
 
     boolean isOptional();
+    
+    void setOptional( boolean optional );
 
     ArtifactVersion getSelectedVersion()
         throws OverConstrainedVersionException;
Index: src/main/java/org/apache/maven/artifact/DefaultArtifact.java
===================================================================
--- src/main/java/org/apache/maven/artifact/DefaultArtifact.java	(revision 348837)
+++ src/main/java/org/apache/maven/artifact/DefaultArtifact.java	(working copy)
@@ -529,6 +529,11 @@
     {
         return optional;
     }
+    
+    public void setOptional( boolean optional )
+    {
+        this.optional = optional;
+    }
 
     public ArtifactVersion getSelectedVersion()
         throws OverConstrainedVersionException
Index: src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactCollector.java
===================================================================
--- src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactCollector.java	(revision 348837)
+++ src/main/java/org/apache/maven/artifact/resolver/DefaultArtifactCollector.java	(working copy)
@@ -122,6 +122,7 @@
             {
                 node.getArtifact().setScope( artifact.getScope() );
             }
+            node.getArtifact().setOptional( artifact.isOptional() );
         }
 
         List previousNodes = (List) resolvedArtifacts.get( key );