diff --git a/test/data/source1.xml b/test/data/source1.xml
index c838d25..cffa4fc 100644
--- a/test/data/source1.xml
+++ b/test/data/source1.xml
@@ -2,7 +2,7 @@
 <source_library title="source library">
         <source name="Source1" type="PointSource">
                 <spectrum type="PowerLaw">
-                        <parameter scale="1e-07" name="Prefactor" min="1e-07" max="1000.0" value="1.73" free="1"/>
+                        <parameter scale="1e-07" name="Prefactor" min="1e-07" max="1000.0" value="1.0" free="1"/>
                         <parameter scale="1.0" name="Index" min="-5.0" max="+5.0" value="-2.1" free="1"/>
                         <parameter scale="1.0" name="Scale" min="10.0" max="1000000.0" value="100.0" free="0"/>
                 </spectrum>