diff --git a/gradle.properties b/gradle.properties
index 4158f2cf..3aec17ee 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -52,5 +52,7 @@ loader_name=forge
 loader_code=1
 java_version=25
 java_toolchain_version=25.0.3+9
+# actions/setup-java names this exact Temurin build with its catalog LTS suffix.
+java_setup_version=25.0.3+9.0.LTS
 gradle_java_version=25
 curseforge_project_id=245586
diff --git a/src/test/java/zone/moddev/mc/orespawn/ReleaseWorkflowContractTest.java b/src/test/java/zone/moddev/mc/orespawn/ReleaseWorkflowContractTest.java
index cae4a237..e3632798 100644
--- a/src/test/java/zone/moddev/mc/orespawn/ReleaseWorkflowContractTest.java
+++ b/src/test/java/zone/moddev/mc/orespawn/ReleaseWorkflowContractTest.java
@@ -23,6 +23,16 @@ void usesOreSpawnSpecificMavenNamespace() throws Exception {
 		assertEquals("zone.moddev.mc.orespawn", properties.getProperty("mod_group"));
 	}
 
+	@Test
+	void declaresTheHostedSelectorForTheExactTemurinToolchain() throws Exception {
+		Properties properties = new Properties();
+		try (InputStream input = Files.newInputStream(Paths.get("gradle.properties"))) {
+			properties.load(input);
+		}
+		assertEquals("25.0.3+9", properties.getProperty("java_toolchain_version"));
+		assertEquals("25.0.3+9.0.LTS", properties.getProperty("java_setup_version"));
+	}
+
 	@Test
 	void verifiesGeneratedMavenCoordinatesBeforeCheckAndPublication() throws Exception {
 		Path buildFile = Paths.get("build.gradle");