diff --git a/clients/java/build.gradle b/clients/java/build.gradle
index 6e152e5..912a056 100644
--- a/clients/java/build.gradle
+++ b/clients/java/build.gradle
@@ -13,18 +13,20 @@ ext {
 
 subprojects {
     group = 'com.zb.mom.ww.mxgateway'
-    version = '0.1.2'
+    version = '0.2.0'
 
     pluginManager.withPlugin('java') {
         java {
+            // Retargeted 21 -> 17 so the artifact loads on Ignition 8.3's JDK 17
+            // (a 17-targeted build still runs on 21+). See roadmap G0.
             toolchain {
-                languageVersion = JavaLanguageVersion.of(21)
+                languageVersion = JavaLanguageVersion.of(17)
             }
         }
 
         tasks.withType(JavaCompile).configureEach {
             options.encoding = 'UTF-8'
-            options.release = 21
+            options.release = 17
         }
 
         tasks.withType(Test).configureEach {
diff --git a/clients/java/zb-mom-ww-mxgateway-client/src/test/java/com/zb/mom/ww/mxgateway/client/GeneratedContractSmokeTests.java b/clients/java/zb-mom-ww-mxgateway-client/src/test/java/com/zb/mom/ww/mxgateway/client/GeneratedContractSmokeTests.java
index dee8855..3c31802 100644
--- a/clients/java/zb-mom-ww-mxgateway-client/src/test/java/com/zb/mom/ww/mxgateway/client/GeneratedContractSmokeTests.java
+++ b/clients/java/zb-mom-ww-mxgateway-client/src/test/java/com/zb/mom/ww/mxgateway/client/GeneratedContractSmokeTests.java
@@ -23,7 +23,9 @@ final class GeneratedContractSmokeTests {
     }
 
     @Test
-    void javaTwentyOneToolchainRunsTests() {
-        assertEquals(21, Runtime.version().feature());
+    void javaSeventeenToolchainRunsTests() {
+        // Pinned to 17: the client is retargeted to JDK 17 so it loads on
+        // Ignition 8.3's JDK 17 runtime (roadmap G0). A 17 build still runs on 21+.
+        assertEquals(17, Runtime.version().feature());
     }
 }