diff --git a/jdom.spec b/jdom.spec
index 0cb2bf0..74168a4 100644
--- a/jdom.spec
+++ b/jdom.spec
@@ -79,7 +79,7 @@ find . -name "*.class" -exec rm -f {} \;
 
 %build
 export CLASSPATH=$(build-classpath xerces-j2 jaxen)
-ant -Dj2se.apidoc=%{_javadocdir}/java package javadoc-link
+ant -Dcompile.source=1.6 -Dcompile.target=1.6 -Dj2se.apidoc=%{_javadocdir}/java package javadoc-link
 
 %install
 %mvn_file : %{name}