diff --git a/src/main/java/org/mastodon/util/TreeUtils.java b/src/main/java/org/mastodon/util/TreeUtils.java
index fbf523ebc..0a8734354 100644
--- a/src/main/java/org/mastodon/util/TreeUtils.java
+++ b/src/main/java/org/mastodon/util/TreeUtils.java
@@ -39,7 +39,6 @@
 import org.mastodon.graph.Vertex;
 import org.mastodon.mamut.model.Model;
 import org.mastodon.mamut.model.Spot;
-import org.mastodon.pool.PoolCollectionWrapper;
 
 public class TreeUtils
 {
@@ -239,7 +238,7 @@ private static < V extends Vertex<E>, E extends Edge< V > > RefSet< V > filterRo
 	public static int getMinTimepoint( final Model model )
 	{
 		int minTimepoint = Integer.MAX_VALUE;
-		for ( Spot spot : model.getGraph().vertices() )
+		for ( final Spot spot : model.getGraph().vertices() )
 			minTimepoint = Math.min( minTimepoint, spot.getTimepoint() );
 		return minTimepoint;
 	}
@@ -252,7 +251,7 @@ public static int getMinTimepoint( final Model model )
 	public static int getMaxTimepoint( final Model model )
 	{
 		int max = 0;
-		for ( Spot spot : model.getGraph().vertices() )
+		for ( final Spot spot : model.getGraph().vertices() )
 			max = Math.max( max, spot.getTimepoint() );
 		return max;
 	}