Maven install:install-file not working for sources

[Dave Rathnow]

Could someone tell me how to install sources into the repository?  As
far as I can make out from the doc, the following command should work:
 
mvn install:install-file -DgroupId=myGroupId-DartifactId=myArtifactId
-Dfile=myArtifact-1.0-sources.jar -Dversion=1.0 -Dpackaging=jar
-DgeneratePom=true -Dclassifier=sources
 
but it doesn't. It overrides the original artifact, in this case my jar
file.
 
Dave.