diff --git a/test/data/sciver/crab_const.xml b/test/data/sciver/crab_const.xml
index 8ebb084..aad1754 100644
--- a/test/data/sciver/crab_const.xml
+++ b/test/data/sciver/crab_const.xml
@@ -2,7 +2,7 @@
 <source_library title="source library">
   <source name="Crab" type="DiffuseSource">
     <spectrum type="PowerLaw">
-      <parameter name="Prefactor" scale="1e-13" value="5.7"  min="1e-07" max="1000.0" free="1"/>
+      <parameter name="Prefactor" scale="1e-12" value="2.0"  min="1e-07" max="1000.0" free="1"/>
       <parameter name="Index"     scale="-1"    value="2.48" min="0.0"   max="+5.0"   free="1"/>
       <parameter name="Scale"     scale="1e6"   value="0.3"  min="0.01"  max="1000.0" free="0"/>
     </spectrum>