Index: src/main/java/org/codehaus/mojo/rpm/FileHelper.java
===================================================================
--- src/main/java/org/codehaus/mojo/rpm/FileHelper.java	(revision 17974)
+++ src/main/java/org/codehaus/mojo/rpm/FileHelper.java	(working copy)
@@ -137,6 +137,10 @@
                     for ( Iterator ait = artlist.iterator(); ait.hasNext(); )
                     {
                         Artifact artifactInstance = (Artifact) ait.next();
+                        if ( !artifactInstance.isResolved() )
+                        {
+                            throw new MojoExecutionException( "Unable to resolve artifact. Maybe you need to run \"mvn install\" first" );
+                        }
                         copyArtifact( artifactInstance, dest, false );
                         map.addCopiedFileNameRelativeToDestination( artifactInstance.getFile().getName() );
                     }