diff --git a/CHANGELOG.md b/CHANGELOG.md
index 57d0e388e0..2a8c2a5c9e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@ This section is for maintaining a changelog for all breaking changes for the cli
 ### Dependencies
 
 ### Changed
+- Restore support for Java 8 ([#767](https://github.com/opensearch-project/opensearch-java/pull/767))
 
 ### Deprecated
 - Deprecated "_toQuery()" in Query and QueryVariant ([#760](https://github.com/opensearch-project/opensearch-java/pull/760)
diff --git a/java-client/build.gradle.kts b/java-client/build.gradle.kts
index b8faacdbc5..3a1169c3ad 100644
--- a/java-client/build.gradle.kts
+++ b/java-client/build.gradle.kts
@@ -63,9 +63,15 @@ configurations {
     }
 }
 
+// The tests are using OpenSearch core test framework, that has JDK-11 baseline
+tasks.named<JavaCompile>("compileTestJava") {
+    sourceCompatibility = JavaVersion.VERSION_11.toString()
+    targetCompatibility = JavaVersion.VERSION_11.toString()
+}
+
 java {
-    targetCompatibility = JavaVersion.VERSION_11
-    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_1_8
+    sourceCompatibility = JavaVersion.VERSION_1_8
 
     withJavadocJar()
     withSourcesJar()
diff --git a/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java b/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
index 2e4145f3bb..313f9c4d1d 100644
--- a/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
+++ b/java-client/src/main/java/org/opensearch/client/transport/aws/AwsSdk2Transport.java
@@ -293,7 +293,7 @@ private <RequestT> SdkHttpFullRequest prepareRequest(
         Map<String, String> params = endpoint.queryParameters(request);
         if (params != null && !params.isEmpty()) {
             char sep = '?';
-            for (var ent : params.entrySet()) {
+            for (Map.Entry<String, String> ent : params.entrySet()) {
                 url.append(sep).append(ent.getKey()).append('=');
                 url.append(URLEncoder.encode(ent.getValue(), StandardCharsets.UTF_8));
                 sep = '&';