diff --git a/test/data/sciver/crab_const.xml b/test/data/sciver/crab_const.xml
new file mode 100644
index 0000000..8ebb084
--- /dev/null
+++ b/test/data/sciver/crab_const.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" standalone="no"?>
+<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="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>
+    <spatialModel type="ConstantValue">
+      <parameter name="Value" scale="1" value="1" min="0.1" max="10" free="0"/>
+    </spatialModel>
+  </source>
+  <source name="Background" type="CTAIrfBackground" instrument="CTA">
+    <spectrum type="PowerLaw">
+      <parameter name="Prefactor" scale="1.0" value="1.0" min="1e-3" max="1e3"    free="1"/>
+      <parameter name="Index"     scale="1.0" value="0.0" min="-5.0" max="+5.0"   free="1"/>
+      <parameter name="Scale"     scale="1e6" value="1.0" min="0.01" max="1000.0" free="0"/>
+    </spectrum>
+  </source>
+</source_library>