diff --git a/src/main/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplay.java b/src/main/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplay.java
index 6ab3bdd542deeba00d006290977b1bbb033a277f..faa98a82871e6410239ebbfc894e4a54c52dbd44 100644
--- a/src/main/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplay.java
+++ b/src/main/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplay.java
@@ -35,12 +35,12 @@ import teetime.framework.AbstractConsumerStage;
  */
 public class CPUUtilizationDisplay extends AbstractConsumerStage<CPUUtilizationRecord> {
 
-	private static final String TOTAL_UTILIZATION = "totalUtilization";
-	private static final String IDLE = "idle";
-	private static final String IRQ = "irq";
-	private static final String NICE = "nice";
-	private static final String SYSTEM = "system";
-	private static final String USER = "user";
+	static final String TOTAL_UTILIZATION = "totalUtilization";
+	static final String IDLE = "idle";
+	static final String IRQ = "irq";
+	static final String NICE = "nice";
+	static final String SYSTEM = "system";
+	static final String USER = "user";
 
 	private final MeterGauge meterGauge;
 	private final XYPlot xyplot;
diff --git a/src/main/java/kieker/analysis/plugin/filter/sink/GCDisplay.java b/src/main/java/kieker/analysis/plugin/filter/sink/GCDisplay.java
index 5ce6d00218286e2173c84f86a970cdb524a92d4f..6bb8da30b70dd5bbedba10f9d44393c97da8568b 100644
--- a/src/main/java/kieker/analysis/plugin/filter/sink/GCDisplay.java
+++ b/src/main/java/kieker/analysis/plugin/filter/sink/GCDisplay.java
@@ -30,8 +30,8 @@ import teetime.framework.AbstractConsumerStage;
  */
 public class GCDisplay extends AbstractConsumerStage<GCRecord> {
 
-	private static final String COLLECTION_TIME = "Collection Time";
-	private static final String COLLECTION_COUNT = "Collection Count";
+	static final String COLLECTION_TIME = "Collection Time";
+	static final String COLLECTION_COUNT = "Collection Count";
 
 	private final XYPlot xyplot;
 
diff --git a/src/test/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplayTest.java b/src/test/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplayTest.java
index 7c7b4e4e30bbaa37fe9451ad3e6f0789bacff056..02281b69ef4f7c2e0e1fdc9ff5f42429050de292 100644
--- a/src/test/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplayTest.java
+++ b/src/test/java/kieker/analysis/plugin/filter/sink/CPUUtilizationDisplayTest.java
@@ -61,12 +61,12 @@ public class CPUUtilizationDisplayTest {
 		final Date date = new Date(TimeUnit.MILLISECONDS.convert(record.getLoggingTimestamp(), recordsTimeUnit));
 		final String minutesAndSeconds = date.toString().substring(14, 19);
 
-		double actualUser = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "user").get(minutesAndSeconds);
-		double actualSystem = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "system").get(minutesAndSeconds);
-		double actualNice = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "nice").get(minutesAndSeconds);
-		double actualIrq = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "irq").get(minutesAndSeconds);
-		double actualTotalUtilization = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "totalUtilization").get(minutesAndSeconds);
-		double actualIdle = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + "idle").get(minutesAndSeconds);
+		double actualUser = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.USER).get(minutesAndSeconds);
+		double actualSystem = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.SYSTEM).get(minutesAndSeconds);
+		double actualNice = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.NICE).get(minutesAndSeconds);
+		double actualIrq = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.IRQ).get(minutesAndSeconds);
+		double actualTotalUtilization = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.TOTAL_UTILIZATION).get(minutesAndSeconds);
+		double actualIdle = (double) cpuUtilFilter.getXYPlot().getEntries(id + " - " + CPUUtilizationDisplay.IDLE).get(minutesAndSeconds);
 
 		assertThat(actualUser / 100, is(user));
 		assertThat(actualSystem / 100, is(system));
diff --git a/src/test/java/kieker/analysis/plugin/filter/sink/GCDisplayTest.java b/src/test/java/kieker/analysis/plugin/filter/sink/GCDisplayTest.java
index 4a7a79f42e4554e54627ed065b8e528b48e3892b..a537654e0dedf566fb1b0412ed70e25d1f6ca778 100644
--- a/src/test/java/kieker/analysis/plugin/filter/sink/GCDisplayTest.java
+++ b/src/test/java/kieker/analysis/plugin/filter/sink/GCDisplayTest.java
@@ -47,8 +47,8 @@ public class GCDisplayTest {
 
 		final String id = record.getHostname() + " - " + record.getVmName() + " - " + record.getGcName();
 
-		long actualCollectionCount = (long) gcDisplayFilter.getXYPlot().getEntries(id + " - " + "Collection Count").get(minutesAndSeconds);
-		long actualCollectionTime = (long) gcDisplayFilter.getXYPlot().getEntries(id + " - " + "Collection Time").get(minutesAndSeconds);
+		long actualCollectionCount = (long) gcDisplayFilter.getXYPlot().getEntries(id + " - " + GCDisplay.COLLECTION_COUNT).get(minutesAndSeconds);
+		long actualCollectionTime = (long) gcDisplayFilter.getXYPlot().getEntries(id + " - " + GCDisplay.COLLECTION_TIME).get(minutesAndSeconds);
 
 		assertThat(actualCollectionCount, is(collectionCount));
 		assertThat(actualCollectionTime, is(collectionTimeMS));