diff --git a/src/test/java/org/matsim/freight/logistics/examples/simulationTrackers/CollectionTrackerTest.java b/src/test/java/org/matsim/freight/logistics/examples/simulationTrackers/CollectionTrackerTest.java
index 76ec9466..6b16b5c1 100644
--- a/src/test/java/org/matsim/freight/logistics/examples/simulationTrackers/CollectionTrackerTest.java
+++ b/src/test/java/org/matsim/freight/logistics/examples/simulationTrackers/CollectionTrackerTest.java
@@ -280,7 +280,7 @@ public void testCollectionTracker() {
 							// (yy I do not understand why we do not need to do this for the end activity of the tour.)
 						}
 					}
-					log.warn("scheduledDistanceCosts=" + scheduledDistanceCosts);
+					log.warn("scheduledDistanceCosts={}", scheduledDistanceCosts);
 				}
 				totalScheduledCosts += scheduledDistanceCosts;
 				assertEquals(scheduledDistanceCosts, trackedDistanceCosts, Math.max(scheduledDistanceCosts, trackedDistanceCosts) * 0.01);
diff --git a/src/test/java/org/matsim/freight/logistics/lspMobsimTests/MultipleShipmentsCompleteLSPMobsimTest.java b/src/test/java/org/matsim/freight/logistics/lspMobsimTests/MultipleShipmentsCompleteLSPMobsimTest.java
index 22df4df0..3217baa3 100644
--- a/src/test/java/org/matsim/freight/logistics/lspMobsimTests/MultipleShipmentsCompleteLSPMobsimTest.java
+++ b/src/test/java/org/matsim/freight/logistics/lspMobsimTests/MultipleShipmentsCompleteLSPMobsimTest.java
@@ -338,7 +338,7 @@ public void initialize() {
 	@Test
 	public void testCompleteLSPMobsim() {
 		for (LspShipment shipment : completeLSP.getLspShipments()) {
-			log.info("comparing shipment: " + shipment.getId());
+			log.info("comparing shipment: {}", shipment.getId());
 			assertFalse(shipment.getShipmentLog().getPlanElements().isEmpty());
 			ArrayList<LspShipmentPlanElement> scheduleElements = new ArrayList<>(LspShipmentUtils.getOrCreateShipmentPlan(completeLSP.getSelectedPlan(), shipment.getId()).getPlanElements().values());
 			scheduleElements.sort(LspShipmentUtils.createShipmentPlanElementComparator());