diff --git a/pom.xml b/pom.xml
index d3f6bf1..2d709ae 100644
--- a/pom.xml
+++ b/pom.xml
@@ -18,7 +18,7 @@
   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
-    <version>3.5.5</version>
+    <version>4.0.0-RC1</version>
   </parent>
 
   <dependencies>
diff --git a/src/main/java/de/ph87/data/series/OneSeriesPointsResponse.java b/src/main/java/de/ph87/data/series/OneSeriesPointsResponse.java
index 834d4ec..ba1f8c7 100644
--- a/src/main/java/de/ph87/data/series/OneSeriesPointsResponse.java
+++ b/src/main/java/de/ph87/data/series/OneSeriesPointsResponse.java
@@ -1,6 +1,6 @@
 package de.ph87.data.series;
 
-import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import tools.jackson.databind.annotation.JsonSerialize;
 import lombok.Data;
 
 import java.util.List;
diff --git a/src/main/java/de/ph87/data/series/OneSeriesPointsResponseSerializer.java b/src/main/java/de/ph87/data/series/OneSeriesPointsResponseSerializer.java
index d71d147..a9917c3 100644
--- a/src/main/java/de/ph87/data/series/OneSeriesPointsResponseSerializer.java
+++ b/src/main/java/de/ph87/data/series/OneSeriesPointsResponseSerializer.java
@@ -1,22 +1,21 @@
 package de.ph87.data.series;
 
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.databind.JsonSerializer;
-import com.fasterxml.jackson.databind.SerializerProvider;
+import tools.jackson.core.JacksonException;
+import tools.jackson.core.JsonGenerator;
+import tools.jackson.databind.SerializationContext;
+import tools.jackson.databind.ValueSerializer;
 
-import java.io.IOException;
-
-public class OneSeriesPointsResponseSerializer extends JsonSerializer<OneSeriesPointsResponse> {
+public class OneSeriesPointsResponseSerializer extends ValueSerializer<OneSeriesPointsResponse> {
 
   @Override
-  public void serialize(final OneSeriesPointsResponse result, final JsonGenerator jsonGenerator, final SerializerProvider serializerProvider) throws IOException {
-    jsonGenerator.writeStartArray();
-    for (final SeriesPoint point : result.points) {
-      jsonGenerator.writeStartArray();
-      point.toJson(jsonGenerator);
-      jsonGenerator.writeEndArray();
+  public void serialize(final OneSeriesPointsResponse value, final JsonGenerator gen, final SerializationContext ctxt) throws JacksonException {
+    gen.writeStartArray();
+    for (final SeriesPoint<?> point : value.points) {
+      gen.writeStartArray();
+      point.toJson(gen);
+      gen.writeEndArray();
     }
-    jsonGenerator.writeEndArray();
+    gen.writeEndArray();
   }
 
 }
diff --git a/src/main/java/de/ph87/data/series/SeriesPoint.java b/src/main/java/de/ph87/data/series/SeriesPoint.java
index f14f255..5cfbdda 100644
--- a/src/main/java/de/ph87/data/series/SeriesPoint.java
+++ b/src/main/java/de/ph87/data/series/SeriesPoint.java
@@ -1,11 +1,10 @@
 package de.ph87.data.series;
 
-import com.fasterxml.jackson.core.JsonGenerator;
 import de.ph87.data.plot.axis.graph.GraphDivisionByZero;
 import de.ph87.data.plot.axis.graph.GraphOperation;
 import lombok.NonNull;
+import tools.jackson.core.JsonGenerator;
 
-import java.io.IOException;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -17,7 +16,7 @@ public interface SeriesPoint<T extends SeriesPoint<T>> {
 
   double getValue();
 
-  void toJson(final JsonGenerator jsonGenerator) throws IOException;
+  void toJson(final JsonGenerator jsonGenerator);
 
   T times(final double factor);
 
diff --git a/src/main/java/de/ph87/data/series/data/bool/BoolPoint.java b/src/main/java/de/ph87/data/series/data/bool/BoolPoint.java
index fb4a47e..d285117 100644
--- a/src/main/java/de/ph87/data/series/data/bool/BoolPoint.java
+++ b/src/main/java/de/ph87/data/series/data/bool/BoolPoint.java
@@ -1,13 +1,12 @@
 package de.ph87.data.series.data.bool;
 
-import com.fasterxml.jackson.core.JsonGenerator;
 import de.ph87.data.plot.axis.graph.GraphDivisionByZero;
 import de.ph87.data.plot.axis.graph.GraphOperation;
 import de.ph87.data.series.SeriesPoint;
 import lombok.Data;
 import lombok.NonNull;
+import tools.jackson.core.JsonGenerator;
 
-import java.io.IOException;
 import java.time.ZonedDateTime;
 
 @Data
@@ -36,7 +35,7 @@ public class BoolPoint implements SeriesPoint<BoolPoint> {
   }
 
   @Override
-  public void toJson(final JsonGenerator jsonGenerator) throws IOException {
+  public void toJson(final JsonGenerator jsonGenerator) {
     jsonGenerator.writeNumber(begin.toEpochSecond());
     jsonGenerator.writeNumber(end.toEpochSecond());
     jsonGenerator.writeNumber(state ? 1 : 0);
diff --git a/src/main/java/de/ph87/data/series/data/delta/Delta.java b/src/main/java/de/ph87/data/series/data/delta/Delta.java
index add7470..161223e 100644
--- a/src/main/java/de/ph87/data/series/data/delta/Delta.java
+++ b/src/main/java/de/ph87/data/series/data/delta/Delta.java
@@ -26,7 +26,6 @@ public abstract class Delta {
   @Column(nullable = false)
   private double first;
 
-  @NonNull
   @Column(nullable = false)
   private double last;
 
@@ -46,7 +45,7 @@ public abstract class Delta {
   @Entity(name = "DeltaFive")
   public static class Five extends Delta {
 
-    public Five(@NonNull final DeltaId id, @NonNull final double value) {
+    public Five(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
@@ -58,7 +57,7 @@ public abstract class Delta {
   @Entity(name = "DeltaHour")
   public static class Hour extends Delta {
 
-    public Hour(@NonNull final DeltaId id, @NonNull final double value) {
+    public Hour(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
@@ -70,7 +69,7 @@ public abstract class Delta {
   @Entity(name = "DeltaDay")
   public static class Day extends Delta {
 
-    public Day(@NonNull final DeltaId id, @NonNull final double value) {
+    public Day(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
@@ -82,7 +81,7 @@ public abstract class Delta {
   @Entity(name = "DeltaWeek")
   public static class Week extends Delta {
 
-    public Week(@NonNull final DeltaId id, @NonNull final double value) {
+    public Week(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
@@ -94,7 +93,7 @@ public abstract class Delta {
   @Entity(name = "DeltaMonth")
   public static class Month extends Delta {
 
-    public Month(@NonNull final DeltaId id, @NonNull final double value) {
+    public Month(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
@@ -106,7 +105,7 @@ public abstract class Delta {
   @Entity(name = "DeltaYear")
   public static class Year extends Delta {
 
-    public Year(@NonNull final DeltaId id, @NonNull final double value) {
+    public Year(@NonNull final DeltaId id, final double value) {
       super(id, value);
     }
 
diff --git a/src/main/java/de/ph87/data/series/data/delta/DeltaPoint.java b/src/main/java/de/ph87/data/series/data/delta/DeltaPoint.java
index 1877f52..098133b 100644
--- a/src/main/java/de/ph87/data/series/data/delta/DeltaPoint.java
+++ b/src/main/java/de/ph87/data/series/data/delta/DeltaPoint.java
@@ -1,13 +1,12 @@
 package de.ph87.data.series.data.delta;
 
-import com.fasterxml.jackson.core.JsonGenerator;
 import de.ph87.data.plot.axis.graph.GraphDivisionByZero;
 import de.ph87.data.plot.axis.graph.GraphOperation;
 import de.ph87.data.series.SeriesPoint;
 import lombok.Data;
 import lombok.NonNull;
+import tools.jackson.core.JsonGenerator;
 
-import java.io.IOException;
 import java.time.ZonedDateTime;
 
 @Data
@@ -24,7 +23,7 @@ public class DeltaPoint implements SeriesPoint<DeltaPoint> {
   }
 
   @Override
-  public void toJson(final JsonGenerator jsonGenerator) throws IOException {
+  public void toJson(final JsonGenerator jsonGenerator) {
     jsonGenerator.writeNumber(date.toEpochSecond());
     jsonGenerator.writeNumber(delta);
   }
diff --git a/src/main/java/de/ph87/data/series/data/varying/Varying.java b/src/main/java/de/ph87/data/series/data/varying/Varying.java
index 8f1c16e..9e73674 100644
--- a/src/main/java/de/ph87/data/series/data/varying/Varying.java
+++ b/src/main/java/de/ph87/data/series/data/varying/Varying.java
@@ -57,7 +57,7 @@ public abstract class Varying {
   @Entity(name = "VaryingFive")
   public static class Five extends Varying {
 
-    public Five(@NonNull final DataId id, @NonNull final double value) {
+    public Five(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
@@ -69,7 +69,7 @@ public abstract class Varying {
   @Entity(name = "VaryingHour")
   public static class Hour extends Varying {
 
-    public Hour(@NonNull final DataId id, @NonNull final double value) {
+    public Hour(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
@@ -81,7 +81,7 @@ public abstract class Varying {
   @Entity(name = "VaryingDay")
   public static class Day extends Varying {
 
-    public Day(@NonNull final DataId id, @NonNull final double value) {
+    public Day(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
@@ -93,7 +93,7 @@ public abstract class Varying {
   @Entity(name = "VaryingWeek")
   public static class Week extends Varying {
 
-    public Week(@NonNull final DataId id, @NonNull final double value) {
+    public Week(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
@@ -105,7 +105,7 @@ public abstract class Varying {
   @Entity(name = "VaryingMonth")
   public static class Month extends Varying {
 
-    public Month(@NonNull final DataId id, @NonNull final double value) {
+    public Month(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
@@ -117,7 +117,7 @@ public abstract class Varying {
   @Entity(name = "VaryingYear")
   public static class Year extends Varying {
 
-    public Year(@NonNull final DataId id, @NonNull final double value) {
+    public Year(@NonNull final DataId id, final double value) {
       super(id, value);
     }
 
diff --git a/src/main/java/de/ph87/data/series/data/varying/VaryingPoint.java b/src/main/java/de/ph87/data/series/data/varying/VaryingPoint.java
index e5e3d54..409fe89 100644
--- a/src/main/java/de/ph87/data/series/data/varying/VaryingPoint.java
+++ b/src/main/java/de/ph87/data/series/data/varying/VaryingPoint.java
@@ -1,13 +1,12 @@
 package de.ph87.data.series.data.varying;
 
-import com.fasterxml.jackson.core.JsonGenerator;
 import de.ph87.data.plot.axis.graph.GraphDivisionByZero;
 import de.ph87.data.plot.axis.graph.GraphOperation;
 import de.ph87.data.series.SeriesPoint;
 import lombok.Data;
 import lombok.NonNull;
+import tools.jackson.core.JsonGenerator;
 
-import java.io.IOException;
 import java.time.ZonedDateTime;
 
 @Data
@@ -36,7 +35,7 @@ public class VaryingPoint implements SeriesPoint<VaryingPoint> {
   }
 
   @Override
-  public void toJson(final JsonGenerator jsonGenerator) throws IOException {
+  public void toJson(final JsonGenerator jsonGenerator) {
     jsonGenerator.writeNumber(date.toEpochSecond());
     jsonGenerator.writeNumber(min);
     jsonGenerator.writeNumber(max);
diff --git a/src/main/java/de/ph87/data/weather/WeatherHour.java b/src/main/java/de/ph87/data/weather/WeatherHour.java
index 4f2d68b..1aef9de 100644
--- a/src/main/java/de/ph87/data/weather/WeatherHour.java
+++ b/src/main/java/de/ph87/data/weather/WeatherHour.java
@@ -13,16 +13,12 @@ public class WeatherHour {
   @NonNull
   public final ZonedDateTime date;
 
-  @NonNull
   public final double clouds;
 
-  @NonNull
   public final double irradiation;
 
-  @NonNull
   public final double precipitation;
 
-  @NonNull
   public final double temperature;
 
   public WeatherHour(@NonNull final BrightSkyDto.Hour dto) {
diff --git a/src/main/java/de/ph87/data/weather/WeatherService.java b/src/main/java/de/ph87/data/weather/WeatherService.java
index f42c75c..dd5eb5e 100644
--- a/src/main/java/de/ph87/data/weather/WeatherService.java
+++ b/src/main/java/de/ph87/data/weather/WeatherService.java
@@ -1,6 +1,6 @@
 package de.ph87.data.weather;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
+import tools.jackson.databind.ObjectMapper;
 import lombok.NonNull;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;