diff --git a/lib/java/gradle/sourceConfiguration.gradle b/lib/java/gradle/sourceConfiguration.gradle
index e3e143a..30f72cc 100644
--- a/lib/java/gradle/sourceConfiguration.gradle
+++ b/lib/java/gradle/sourceConfiguration.gradle
@@ -39,8 +39,8 @@
     options.encoding = 'UTF-8'
     options.debug = true
     options.deprecation = true
-    // the following is to build with Java 11 specifications, even when building with later JDK
-    options.release = 11
+    // the following is to build with Java 8 specifications, even when building with later JDK
+    options.release = 8
     options.compilerArgs += [
             '-Werror',
             '-Xlint:deprecation',
diff --git a/lib/java/src/test/java/org/apache/thrift/transport/TestTSaslTransports.java b/lib/java/src/test/java/org/apache/thrift/transport/TestTSaslTransports.java
index d4f8fff..224da21 100644
--- a/lib/java/src/test/java/org/apache/thrift/transport/TestTSaslTransports.java
+++ b/lib/java/src/test/java/org/apache/thrift/transport/TestTSaslTransports.java
@@ -492,7 +492,7 @@
 
   public static class SaslAnonymousProvider extends java.security.Provider {
     public SaslAnonymousProvider() {
-      super("ThriftSaslAnonymous", "1.0", "Thrift Anonymous SASL provider");
+      super("ThriftSaslAnonymous", 1.0, "Thrift Anonymous SASL provider");
       put("SaslClientFactory.ANONYMOUS", SaslAnonymousFactory.class.getName());
       put("SaslServerFactory.ANONYMOUS", SaslAnonymousFactory.class.getName());
     }
diff --git a/lib/kotlin/build.gradle.kts b/lib/kotlin/build.gradle.kts
index 0ec8859..cd52e7f 100644
--- a/lib/kotlin/build.gradle.kts
+++ b/lib/kotlin/build.gradle.kts
@@ -36,10 +36,14 @@
 
 kotlin {
     jvmToolchain {
-        (this as JavaToolchainSpec).languageVersion.set(JavaLanguageVersion.of(11))
+        (this as JavaToolchainSpec).languageVersion.set(JavaLanguageVersion.of(8))
     }
 }
 
+tasks.withType<KotlinCompile> {
+    kotlinOptions.jvmTarget = "1.8"
+}
+
 tasks {
     if (JavaVersion.current().isJava11Compatible) {
         ktfmt {