diff --git a/examples/streaming-example/build.gradle.kts b/examples/streaming-example/build.gradle.kts
index 02fbc35cd..cd8b0aa61 100644
--- a/examples/streaming-example/build.gradle.kts
+++ b/examples/streaming-example/build.gradle.kts
@@ -13,7 +13,7 @@ repositories {
 }
 
 dependencies {
-    implementation("io.getunleash:unleash-client-java:11.1.0")
-    implementation("com.launchdarkly:okhttp-eventsource:4.1.1")
+    implementation("io.getunleash:unleash-client-java:12.2.1-SNAPSHOT")
+    implementation("com.launchdarkly:okhttp-eventsource:4.2.0")
     implementation("ch.qos.logback:logback-classic:1.5.18")
-}
\ No newline at end of file
+}
diff --git a/examples/streaming-example/gradle/wrapper/gradle-wrapper.properties b/examples/streaming-example/gradle/wrapper/gradle-wrapper.properties
index d6e308a63..221c4f982 100644
--- a/examples/streaming-example/gradle/wrapper/gradle-wrapper.properties
+++ b/examples/streaming-example/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.12-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/examples/streaming-example/src/main/java/io/getunleash/example/StreamingExample.java b/examples/streaming-example/src/main/java/io/getunleash/example/StreamingExample.java
index ad6f9e072..b2f70fd60 100644
--- a/examples/streaming-example/src/main/java/io/getunleash/example/StreamingExample.java
+++ b/examples/streaming-example/src/main/java/io/getunleash/example/StreamingExample.java
@@ -12,40 +12,57 @@ public class StreamingExample {
     private static Unleash unleash;
 
     private static class StreamingEventSubscriber implements UnleashSubscriber {
+
         @Override
         public void togglesFetched(ClientFeaturesResponse toggleResponse) {
             System.out.println("[STREAMING EVENT] Features updated");
             if (unleash != null) {
                 boolean isEnabled = unleash.isEnabled("streaming_flag");
-                System.out.println("  streaming_flag: " + (isEnabled ? "ENABLED" : "DISABLED"));
+                System.out.println(
+                    "  streaming_flag: " + (isEnabled ? "ENABLED" : "DISABLED")
+                );
+                System.out.println(
+                    "  test devices flag: " + unleash.isEnabled("devices")
+                );
             }
         }
 
         @Override
         public void onError(UnleashException unleashException) {
-            System.err.println("[STREAMING ERROR] " + unleashException.getMessage());
+            System.err.println(
+                "[STREAMING ERROR] " + unleashException.getMessage()
+            );
         }
     }
 
     public static void main(String[] args) {
         StreamingEventSubscriber subscriber = new StreamingEventSubscriber();
 
-        UnleashConfig config =
-                UnleashConfig.builder()
-                        .appName("streaming-example")
-                        .instanceId("streaming-example-instance")
-                        .unleashAPI(getOrElse("UNLEASH_API_URL", "https://app.unleash-hosted.com/demo/api"))
-                        .customHttpHeader(
-                                "Authorization",
-                                getOrElse("UNLEASH_API_TOKEN",
-                                        "*:development.25a06b75248528f8ca93ce179dcdd141aedfb632231e0d21fd8ff349"))
-                        .experimentalStreamingMode()
-                        .subscriber(subscriber)
-                        .build();
+        UnleashConfig config = UnleashConfig.builder()
+            .appName("streaming-example")
+            .instanceId("streaming-example-instance")
+            .unleashAPI(
+                getOrElse(
+                    "UNLEASH_API_URL",
+                    "https://app.unleash-hosted.com/demo/api"
+                )
+            )
+            .customHttpHeader(
+                "Authorization",
+                getOrElse(
+                    "UNLEASH_API_TOKEN",
+                    "*:development.25a06b75248528f8ca93ce179dcdd141aedfb632231e0d21fd8ff349"
+                )
+            )
+            .experimentalStreamingMode()
+            .subscriber(subscriber)
+            .build();
 
         unleash = new DefaultUnleash(config);
 
-        System.out.println("Streaming client started. Waiting for events... (Press Ctrl+C to exit)");
+        System.out.println(
+            "Streaming client started. Waiting for events... (Press Ctrl+C to exit)"
+        );
 
         try {
             Thread.currentThread().join();
@@ -62,4 +79,4 @@ public static String getOrElse(String key, String defaultValue) {
         }
         return value;
     }
-}
\ No newline at end of file
+}
diff --git a/pom.xml b/pom.xml
index f4afca2db..bfc30601d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -7,7 +7,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <version.unleash.specification>5.2.2</version.unleash.specification>
+        <version.unleash.specification>6.1.0</version.unleash.specification>
         <arguments />
         <version.assertj>3.27.7</version.assertj>
         <version.gson>2.13.2</version.gson>
@@ -15,9 +15,9 @@
         <version.junit5>5.14.0</version.junit5>
         <version.logback>1.5.25</version.logback>
         <version.mockito>5.20.0</version.mockito>
-        <version.okhttp>4.12.0</version.okhttp>
+        <version.okhttp>5.3.2</version.okhttp>
         <version.slf4j>2.0.17</version.slf4j>
-        <version.wiremock>3.9.2</version.wiremock>
+        <version.wiremock>3.13.2</version.wiremock>
     </properties>
 
     <name>io.getunleash:unleash-client-java</name>
@@ -61,7 +61,7 @@
         <dependency>
             <groupId>io.getunleash</groupId>
             <artifactId>yggdrasil-engine</artifactId>
-            <version>0.5.1</version>
+            <version>1.0.1</version>
         </dependency>
         <dependency>
             <groupId>com.google.code.gson</groupId>
@@ -70,14 +70,14 @@
         </dependency>
         <dependency>
             <groupId>com.squareup.okhttp3</groupId>
-            <artifactId>okhttp</artifactId>
+            <artifactId>okhttp-jvm</artifactId>
             <version>${version.okhttp}</version>
             <optional>true</optional>
         </dependency>
         <dependency>
             <groupId>com.launchdarkly</groupId>
             <artifactId>okhttp-eventsource</artifactId>
-            <version>4.1.1</version>
+            <version>4.2.0</version>
         </dependency>
 
         <dependency>
diff --git a/src/main/java/io/getunleash/DefaultUnleash.java b/src/main/java/io/getunleash/DefaultUnleash.java
index 9ea99fa8d..be8522ef0 100644
--- a/src/main/java/io/getunleash/DefaultUnleash.java
+++ b/src/main/java/io/getunleash/DefaultUnleash.java
@@ -228,7 +228,8 @@ public List<EvaluatedToggle> evaluateAllToggles(UnleashContext context) {
                                 UnleashContext enhancedContext = context.applyStaticFields(config);
                                 FlatResponse<VariantDef> response =
                                         featureRepository.getVariant(toggleName, enhancedContext);
-                                Optional<VariantDef> variantDef = Optional.of(response.value);
+                                Optional<VariantDef> variantDef =
+                                        Optional.ofNullable(response).map(r -> r.value);
                                 Variant variant =
                                         YggdrasilAdapters.adapt(variantDef, DISABLED_VARIANT);
                                 return new EvaluatedToggle(
diff --git a/src/main/java/io/getunleash/metric/OkHttpMetricsSender.java b/src/main/java/io/getunleash/metric/OkHttpMetricsSender.java
index 36015f11b..ff888f3bf 100644
--- a/src/main/java/io/getunleash/metric/OkHttpMetricsSender.java
+++ b/src/main/java/io/getunleash/metric/OkHttpMetricsSender.java
@@ -15,12 +15,7 @@
 import java.time.LocalDateTime;
 import java.util.Objects;
 import java.util.concurrent.atomic.AtomicLong;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
-import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.RequestBody;
-import okhttp3.Response;
+import okhttp3.*;
 
 public class OkHttpMetricsSender implements MetricSender {
     private final UnleashConfig config;
diff --git a/src/main/java/io/getunleash/repository/FeatureRepositoryImpl.java b/src/main/java/io/getunleash/repository/FeatureRepositoryImpl.java
index 35de8b0ad..8c5aea8be 100644
--- a/src/main/java/io/getunleash/repository/FeatureRepositoryImpl.java
+++ b/src/main/java/io/getunleash/repository/FeatureRepositoryImpl.java
@@ -60,7 +60,7 @@ public FeatureRepositoryImpl(UnleashConfig unleashConfig, UnleashEngine engine)
 
     private void initCollections(UnleashScheduledExecutor executor) {
         Optional<String> features = this.featureBackupHandler.read();
-        if (!features.isPresent() && this.bootstrapper != null) {
+        if (features.isEmpty() && this.bootstrapper != null) {
             features = this.bootstrapper.read();
         }
         if (features.isPresent()) {