diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index fe7fff9ad3e03..a32644fa6542c 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -61,7 +61,7 @@ Properties props = VersionPropertiesLoader.loadBuildSrcVersion(project.file('ver
 version = props.getProperty("opensearch")
 
 def generateVersionProperties = tasks.register("generateVersionProperties", WriteProperties) {
-  outputFile = "${buildDir}/version.properties"
+  destinationFile = file("${buildDir}/version.properties")
   comment = 'Generated version properties'
   properties(props)
 }
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/OpenSearchTestBasePlugin.java b/buildSrc/src/main/java/org/opensearch/gradle/OpenSearchTestBasePlugin.java
index cdf22407f6076..451bd9cf83053 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/OpenSearchTestBasePlugin.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/OpenSearchTestBasePlugin.java
@@ -35,6 +35,7 @@
 import com.github.jengelman.gradle.plugins.shadow.ShadowBasePlugin;
 import org.opensearch.gradle.info.BuildParams;
 import org.opensearch.gradle.info.GlobalBuildInfoPlugin;
+import org.opensearch.gradle.jvm.JvmTestSuiteHelper;
 import org.opensearch.gradle.test.ErrorReportingTestListener;
 import org.opensearch.gradle.util.Util;
 import org.gradle.api.Action;
@@ -223,7 +224,15 @@ public void execute(Task t) {
                 // Add the shadow JAR artifact itself
                 FileCollection shadowJar = project.files(project.getTasks().named("shadowJar"));
 
-                test.setClasspath(test.getClasspath().minus(mainRuntime).plus(shadowConfig).plus(shadowJar));
+                // See please https://docs.gradle.org/8.1/userguide/upgrading_version_8.html#test_task_default_classpath
+                test.setClasspath(
+                    JvmTestSuiteHelper.getDefaultTestSuite(project)
+                        .map(suite -> suite.getSources().getRuntimeClasspath())
+                        .orElseGet(() -> test.getClasspath())
+                        .minus(mainRuntime)
+                        .plus(shadowConfig)
+                        .plus(shadowJar)
+                );
             });
         });
     }
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/jvm/JvmTestSuiteHelper.java b/buildSrc/src/main/java/org/opensearch/gradle/jvm/JvmTestSuiteHelper.java
new file mode 100644
index 0000000000000..3b8e88c9f1a8f
--- /dev/null
+++ b/buildSrc/src/main/java/org/opensearch/gradle/jvm/JvmTestSuiteHelper.java
@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.gradle.jvm;
+
+import org.gradle.api.Project;
+import org.gradle.api.plugins.JvmTestSuitePlugin;
+import org.gradle.api.plugins.jvm.JvmTestSuite;
+import org.gradle.testing.base.TestSuite;
+import org.gradle.testing.base.TestingExtension;
+
+import java.util.Optional;
+
+public final class JvmTestSuiteHelper {
+    private JvmTestSuiteHelper() {}
+
+    /**
+     * Gets the default test suite. This method assumes the Java plugin is applied,
+     * adapted from {@link org.gradle.api.plugins.internal.JavaPluginHelper} since it is not
+     * available in Gradle releases predated 8.1.
+     */
+    public static Optional<JvmTestSuite> getDefaultTestSuite(Project project) {
+        TestingExtension testing = project.getExtensions().findByType(TestingExtension.class);
+        if (testing == null) {
+            return Optional.empty();
+        }
+
+        TestSuite defaultTestSuite = testing.getSuites().findByName(JvmTestSuitePlugin.DEFAULT_TEST_SUITE_NAME);
+        if (!(defaultTestSuite instanceof JvmTestSuite)) {
+            return Optional.empty();
+        }
+
+        return Optional.of((JvmTestSuite) defaultTestSuite);
+    }
+}
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionsTasks.java b/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionsTasks.java
index 5e42cc99dd79e..dad3bfca5f67d 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionsTasks.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/precommit/TestingConventionsTasks.java
@@ -32,6 +32,8 @@
 package org.opensearch.gradle.precommit;
 
 import groovy.lang.Closure;
+
+import org.opensearch.gradle.jvm.JvmTestSuiteHelper;
 import org.opensearch.gradle.util.GradleUtils;
 import org.opensearch.gradle.util.Util;
 import org.gradle.api.DefaultTask;
@@ -39,6 +41,7 @@
 import org.gradle.api.Task;
 import org.gradle.api.file.FileCollection;
 import org.gradle.api.file.FileTree;
+import org.gradle.api.plugins.jvm.JvmTestSuite;
 import org.gradle.api.tasks.Classpath;
 import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.OutputFile;
@@ -46,6 +49,9 @@
 import org.gradle.api.tasks.SourceSetContainer;
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.api.tasks.testing.Test;
+import org.gradle.api.tasks.util.PatternFilterable;
+import org.gradle.api.tasks.util.PatternSet;
+import org.gradle.internal.Factory;
 
 import java.io.File;
 import java.io.IOException;
@@ -70,6 +76,8 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import javax.inject.Inject;
+
 public class TestingConventionsTasks extends DefaultTask {
 
     private static final String TEST_METHOD_PREFIX = "test";
@@ -85,13 +93,39 @@ public TestingConventionsTasks() {
         naming = getProject().container(TestingConventionRule.class);
     }
 
+    @Inject
+    protected Factory<PatternSet> getPatternSetFactory() {
+        throw new UnsupportedOperationException();
+    }
+
     @Input
     public Map<String, Set<File>> getClassFilesPerEnabledTask() {
         return getProject().getTasks()
             .withType(Test.class)
             .stream()
             .filter(Task::getEnabled)
-            .collect(Collectors.toMap(Task::getPath, task -> task.getCandidateClassFiles().getFiles()));
+            .collect(Collectors.toMap(Task::getPath, task -> {
+                // See please https://docs.gradle.org/8.1/userguide/upgrading_version_8.html#test_task_default_classpath
+                final JvmTestSuite jvmTestSuite = JvmTestSuiteHelper.getDefaultTestSuite(getProject()).orElse(null);
+                if (jvmTestSuite != null) {
+                    final PatternFilterable patternSet = getPatternSetFactory().create()
+                        .include(task.getIncludes())
+                        .exclude(task.getExcludes());
+
+                    final Set<File> files = jvmTestSuite.getSources()
+                        .getOutput()
+                        .getClassesDirs()
+                        .getAsFileTree()
+                        .matching(patternSet)
+                        .getFiles();
+
+                    if (!files.isEmpty()) {
+                        return files;
+                    }
+                }
+
+                return task.getCandidateClassFiles().getFiles();
+            }));
     }
 
     @Input
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/RestIntegTestTask.java b/buildSrc/src/main/java/org/opensearch/gradle/test/RestIntegTestTask.java
index d1671146d0b77..87aa3ea4eae8d 100644
--- a/buildSrc/src/main/java/org/opensearch/gradle/test/RestIntegTestTask.java
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/RestIntegTestTask.java
@@ -33,6 +33,10 @@
 package org.opensearch.gradle.test;
 
 import org.opensearch.gradle.testclusters.StandaloneRestIntegTestTask;
+
+import groovy.lang.Closure;
+
+import org.gradle.api.Task;
 import org.gradle.api.tasks.CacheableTask;
 
 /**
@@ -41,4 +45,12 @@
  * conventional configured tasks of {@link RestIntegTestTask}
  */
 @CacheableTask
-public class RestIntegTestTask extends StandaloneRestIntegTestTask {}
+public class RestIntegTestTask extends StandaloneRestIntegTestTask implements TestSuiteConventionMappings {
+    @SuppressWarnings("rawtypes")
+    @Override
+    public Task configure(Closure closure) {
+        final Task t = super.configure(closure);
+        applyConventionMapping(getProject(), getConventionMapping());
+        return t;
+    }
+}
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/TestSuiteConventionMappings.java b/buildSrc/src/main/java/org/opensearch/gradle/test/TestSuiteConventionMappings.java
new file mode 100644
index 0000000000000..12096b8d365f4
--- /dev/null
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/TestSuiteConventionMappings.java
@@ -0,0 +1,24 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.gradle.test;
+
+import org.gradle.api.Project;
+import org.gradle.api.internal.ConventionMapping;
+import org.opensearch.gradle.jvm.JvmTestSuiteHelper;
+
+// Temporary workaround for https://docs.gradle.org/8.1/userguide/upgrading_version_8.html#test_task_default_classpath
+interface TestSuiteConventionMappings {
+    default void applyConventionMapping(Project project, ConventionMapping conventionMapping) {
+        JvmTestSuiteHelper.getDefaultTestSuite(project).ifPresent(defaultTestSuite -> {
+            conventionMapping.map("testClassesDirs", () -> { return defaultTestSuite.getSources().getOutput().getClassesDirs(); });
+
+            conventionMapping.map("classpath", () -> { return defaultTestSuite.getSources().getRuntimeClasspath(); });
+        });
+    }
+}
diff --git a/buildSrc/src/main/java/org/opensearch/gradle/test/TestTask.java b/buildSrc/src/main/java/org/opensearch/gradle/test/TestTask.java
new file mode 100644
index 0000000000000..837660d4618be
--- /dev/null
+++ b/buildSrc/src/main/java/org/opensearch/gradle/test/TestTask.java
@@ -0,0 +1,26 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.gradle.test;
+
+import groovy.lang.Closure;
+
+import org.gradle.api.Task;
+import org.gradle.api.tasks.CacheableTask;
+import org.gradle.api.tasks.testing.Test;
+
+@CacheableTask
+public class TestTask extends Test implements TestSuiteConventionMappings {
+    @SuppressWarnings("rawtypes")
+    @Override
+    public Task configure(Closure closure) {
+        final Task t = super.configure(closure);
+        applyConventionMapping(getProject(), getConventionMapping());
+        return t;
+    }
+}
diff --git a/gradle/code-coverage.gradle b/gradle/code-coverage.gradle
index 7f8af147e236c..d5a717b5ea720 100644
--- a/gradle/code-coverage.gradle
+++ b/gradle/code-coverage.gradle
@@ -19,7 +19,7 @@ repositories {
 
 allprojects {
   plugins.withId('jacoco') {
-    jacoco.toolVersion = '0.8.8'
+    jacoco.toolVersion = '0.8.9'
   }
 }
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index ccebba7710dea..c1962a79e29d3 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 21b7e71e15d65..9b615e6c35f01 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -11,7 +11,7 @@
 
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionSha256Sum=47a5bfed9ef814f90f8debcbbb315e8e7c654109acd224595ea39fca95c5d4da
+distributionSha256Sum=2cbafcd2c47a101cb2165f636b4677fac0b954949c9429c1c988da399defe6a9
diff --git a/gradlew b/gradlew
index 79a61d421cc4e..aeb74cbb43e39 100755
--- a/gradlew
+++ b/gradlew
@@ -85,9 +85,6 @@ done
 APP_BASE_NAME=${0##*/}
 APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
 
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
-
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
 
@@ -197,6 +194,10 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
 # Collect all arguments for the java command;
 #   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
 #     shell script including quotes and variable substitutions, so put them in
diff --git a/modules/transport-netty4/build.gradle b/modules/transport-netty4/build.gradle
index a68d70d124094..4c245ec517bbd 100644
--- a/modules/transport-netty4/build.gradle
+++ b/modules/transport-netty4/build.gradle
@@ -31,6 +31,7 @@
 
 import org.opensearch.gradle.info.BuildParams
 import org.opensearch.gradle.test.RestIntegTestTask
+import org.opensearch.gradle.test.TestTask
 import org.opensearch.gradle.test.rest.JavaRestTestPlugin
 import org.opensearch.gradle.test.InternalClusterTestPlugin
 
@@ -92,13 +93,13 @@ javaRestTest {
   systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
 }
 
-TaskProvider<Test> pooledTest = tasks.register("pooledTest", Test) {
+TaskProvider<Test> pooledTest = tasks.register("pooledTest", TestTask) {
   include '**/*Tests.class'
   systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
   systemProperty 'opensearch.use_unpooled_allocator', 'false'
 }
 
-TaskProvider<Test> pooledInternalClusterTest = tasks.register("pooledInternalClusterTest", Test) {
+TaskProvider<Test> pooledInternalClusterTest = tasks.register("pooledInternalClusterTest", TestTask) {
   include '**/*IT.class'
   systemProperty 'opensearch.set.netty.runtime.available.processors', 'false'
   systemProperty 'opensearch.use_unpooled_allocator', 'false'
diff --git a/plugins/repository-hdfs/build.gradle b/plugins/repository-hdfs/build.gradle
index c1bb9181df151..c1aaa184d59db 100644
--- a/plugins/repository-hdfs/build.gradle
+++ b/plugins/repository-hdfs/build.gradle
@@ -227,7 +227,8 @@ for (String integTestTaskName : ['integTestHa', 'integTestSecure', 'integTestSec
             .resolve("ports")
         }
         nonInputProperties.systemProperty "test.hdfs-fixture.ports", file("$portsFileDir/ports")
-        classpath += files(portsFileDir)
+        // See please https://docs.gradle.org/8.1/userguide/upgrading_version_8.html#test_task_default_classpath
+        classpath = testing.suites.test.sources.runtimeClasspath + files(portsFileDir)
         // Copy ports file to separate location which is placed on the test classpath
         doFirst {
           mkdir(portsFileDir)
diff --git a/plugins/repository-s3/build.gradle b/plugins/repository-s3/build.gradle
index de9617d7bb608..9e239950cac69 100644
--- a/plugins/repository-s3/build.gradle
+++ b/plugins/repository-s3/build.gradle
@@ -31,6 +31,7 @@
 import org.opensearch.gradle.MavenFilteringHack
 import org.opensearch.gradle.info.BuildParams
 import org.opensearch.gradle.test.RestIntegTestTask
+import org.opensearch.gradle.test.TestTask
 import org.opensearch.gradle.test.rest.YamlRestTestPlugin
 import org.opensearch.gradle.test.InternalClusterTestPlugin
 
@@ -86,7 +87,7 @@ bundlePlugin {
   }
 }
 
-task testRepositoryCreds(type: Test) {
+task testRepositoryCreds(type: TestTask) {
   include '**/RepositoryCredentialsTests.class'
   systemProperty 'opensearch.allow_insecure_settings', 'true'
 }
diff --git a/qa/wildfly/build.gradle b/qa/wildfly/build.gradle
index 353f9d54f91e3..75c94e7843e07 100644
--- a/qa/wildfly/build.gradle
+++ b/qa/wildfly/build.gradle
@@ -30,6 +30,7 @@
 
 import org.opensearch.gradle.Architecture
 import org.opensearch.gradle.VersionProperties
+import org.opensearch.gradle.test.TestTask
 
 apply plugin: 'war'
 apply plugin: 'opensearch.build'
@@ -81,7 +82,7 @@ dockerCompose {
   useComposeFiles = ['docker-compose.yml']
 }
 
-tasks.register("integTest", Test) {
+tasks.register("integTest", TestTask) {
   outputs.doNotCacheIf('Build cache is disabled for Docker tests') { true }
   maxParallelForks = '1'
   include '**/*IT.class'