diff --git a/pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/RuntimeUtils.java b/pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/RuntimeUtils.java
index 1fb7650b1e8fb3..329fbc65104074 100644
--- a/pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/RuntimeUtils.java
+++ b/pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/RuntimeUtils.java
@@ -255,6 +255,10 @@ public static List<String> getGoInstanceCmd(InstanceConfig instanceConfig,
         return args;
     }
 
+    public static boolean isJavaVersion9OrMore() {
+        return !System.getProperty("java.version").startsWith("1.");
+    }
+
 
     public static List<String> getCmd(InstanceConfig instanceConfig,
                                       String instanceFile,
@@ -320,6 +324,11 @@ public static List<String> getCmd(InstanceConfig instanceConfig,
 
             args.add("-Dio.netty.tryReflectionSetAccessible=true");
 
+            // Needed for netty.DnsResolverUtil on JDK9+
+            if (isJavaVersion9OrMore()) {
+                args.add("--add-opens java.base/sun.net=ALL-UNNAMED");
+            }
+
             if (instanceConfig.getAdditionalJavaRuntimeArguments() != null) {
                 args.addAll(instanceConfig.getAdditionalJavaRuntimeArguments());
             }
diff --git a/pulsar-functions/runtime/src/test/java/org/apache/pulsar/functions/runtime/process/ProcessRuntimeTest.java b/pulsar-functions/runtime/src/test/java/org/apache/pulsar/functions/runtime/process/ProcessRuntimeTest.java
index 301e38ee820867..92d8bcfcfa2018 100644
--- a/pulsar-functions/runtime/src/test/java/org/apache/pulsar/functions/runtime/process/ProcessRuntimeTest.java
+++ b/pulsar-functions/runtime/src/test/java/org/apache/pulsar/functions/runtime/process/ProcessRuntimeTest.java
@@ -20,6 +20,7 @@
 package org.apache.pulsar.functions.runtime.process;
 
 import static org.apache.pulsar.functions.runtime.RuntimeUtils.FUNCTIONS_INSTANCE_CLASSPATH;
+import static org.mockito.ArgumentMatchers.any;
 import static org.testng.Assert.assertEquals;
 import static org.testng.Assert.assertTrue;
 
@@ -43,6 +44,7 @@
 import org.apache.pulsar.functions.proto.Function;
 import org.apache.pulsar.functions.proto.Function.ConsumerSpec;
 import org.apache.pulsar.functions.proto.Function.FunctionDetails;
+import org.apache.pulsar.functions.runtime.RuntimeUtils;
 import org.apache.pulsar.functions.runtime.thread.ThreadRuntime;
 import org.apache.pulsar.functions.secretsprovider.ClearTextSecretsProvider;
 import org.apache.pulsar.functions.secretsproviderconfigurator.SecretsProviderConfigurator;
@@ -50,6 +52,7 @@
 import org.apache.pulsar.functions.worker.ConnectorsManager;
 import org.apache.pulsar.functions.worker.FunctionsManager;
 import org.apache.pulsar.functions.worker.WorkerConfig;
+import org.mockito.MockedStatic;
 import org.mockito.Mockito;
 import org.testng.annotations.AfterMethod;
 import org.testng.annotations.BeforeClass;
@@ -283,14 +286,18 @@ private void verifyJavaInstance(InstanceConfig config, Path depsDir) throws Exce
     }
 
     private void verifyJavaInstance(InstanceConfig config, Path depsDir, String webServiceUrl) throws Exception {
-        ProcessRuntime container = factory.createContainer(config, userJarFile, null, 30l);
-        List<String> args = container.getProcessArgs();
+        List<String> args;
+        try (MockedStatic<RuntimeUtils> runtimeUtils = Mockito.mockStatic(RuntimeUtils.class, Mockito.CALLS_REAL_METHODS)) {
+            runtimeUtils.when(RuntimeUtils::isJavaVersion9OrMore).thenReturn(true);
+            ProcessRuntime container = factory.createContainer(config, userJarFile, null, 30l);
+            args = container.getProcessArgs();
+        }
 
         String classpath = javaInstanceJarFile;
         String extraDepsEnv;
         int portArg;
         int metricsPortArg;
-        int totalArgCount = 42;
+        int totalArgCount = 43;
         if (webServiceUrl != null && config.isExposePulsarAdminClientEnabled()) {
             totalArgCount += 3;
         }
@@ -298,13 +305,13 @@ private void verifyJavaInstance(InstanceConfig config, Path depsDir, String webS
             assertEquals(args.size(), totalArgCount);
             extraDepsEnv = " -Dpulsar.functions.extra.dependencies.dir=" + depsDir;
             classpath = classpath + ":" + depsDir + "/*";
-            portArg = 25;
-            metricsPortArg = 27;
+            portArg = 26;
+            metricsPortArg = 28;
         } else {
             assertEquals(args.size(), totalArgCount-1);
             extraDepsEnv = "";
-            portArg = 24;
-            metricsPortArg = 26;
+            portArg = 25;
+            metricsPortArg = 27;
         }
         if (webServiceUrl != null && config.isExposePulsarAdminClientEnabled()) {
             portArg += 3;
@@ -321,6 +328,7 @@ private void verifyJavaInstance(InstanceConfig config, Path depsDir, String webS
                 + "-Dpulsar.function.log.dir=" + logDirectory + "/functions/" + FunctionCommon.getFullyQualifiedName(config.getFunctionDetails())
                 + " -Dpulsar.function.log.file=" + config.getFunctionDetails().getName() + "-" + config.getInstanceId()
                 + " -Dio.netty.tryReflectionSetAccessible=true"
+                + " --add-opens java.base/sun.net=ALL-UNNAMED"
                 + " org.apache.pulsar.functions.instance.JavaInstanceMain"
                 + " --jar " + userJarFile + " --instance_id "
                 + config.getInstanceId() + " --function_id " + config.getFunctionId()