diff --git a/data/input/grid.xml b/data/input/grid.xml
index 5ca1d3dd6b9c246cb91e6cf161a3d500bedf00ef..d7ed7bec797bb794e64f0c0101aee79ac6ea962c 100644
--- a/data/input/grid.xml
+++ b/data/input/grid.xml
@@ -1,11 +1,12 @@
-<?xml version="1.0" encoding="ISO-8859-1"?> 
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!DOCTYPE xml>
 <pikelake.Grid>
 	<torusType>BOTH</torusType>
 	<neighborsType>NEIGHBORHOOD_VON_NEUMANN</neighborsType>
-  <preyCarryingCapacity>50</preyCarryingCapacity>
-  <gridWidth>10</gridWidth>
-  <gridHeight>10</gridHeight>
-  <habitatValue0>0.25</habitatValue0>
-  <habitatValue1>0.5</habitatValue1>
-  <habitatValue2>1</habitatValue2>
+	<preyCarryingCapacity>50</preyCarryingCapacity>
+	<gridWidth>10</gridWidth>
+	<gridHeight>10</gridHeight>
+	<habitatValue0>0.25</habitatValue0>
+	<habitatValue1>0.5</habitatValue1>
+	<habitatValue2>1</habitatValue2>
 </pikelake.Grid>
\ No newline at end of file