--- tophat2_wrapper.xml 2012-09-12 11:41:46.000000000 -0400
+++ tophat2_wrapper_withreqs.xml    2012-09-14 13:23:25.000000000 -0400
@@ -3,7 +3,8 @@
     <description>Gapped-read mapper for RNA-seq data</description>
     <version_command>tophat2 --version</version_command>
     <requirements>
-        <requirement type="package">tophat2</requirement>
+        <requirement type="package" version="2.0.0-beta7">bowtie2</requirement>
+        <requirement type="package" version="2.0.4">tophat2</requirement>
     </requirements>
     <command interpreter="python">
         tophat2_wrapper.py