--- a/feature_alignment.xml	Mon May 11 14:25:57 2015 -0400
+++ b/feature_alignment.xml	Thu May 21 11:17:49 2015 -0400
@@ -1,10 +1,14 @@
 <tool id="feature_alignment" name="Feature Alignment" version="0.1">
     <description>of peakgroups below a FDR</description>
+    <requirements>
+        <requirement type="package" version="2.7">python</requirement>
+        <requirement type="package" version="0.3.2">msproteomicstools</requirement>
+    </requirements>
     <stdio>
         <exit_code level="fatal" range="1:"/>
     </stdio>
     <version_command>feature_alignment.py --version</version_command>
-    <command interpreter="python">
+    <command>
 <![CDATA[
     feature_alignment.py 
         --in #'" "'.join([ $file for $file in $inputs ])#