diff --git a/src/integrationTest/java/org/opensearch/test/framework/cluster/TestRestClient.java b/src/integrationTest/java/org/opensearch/test/framework/cluster/TestRestClient.java
index 3d8fe6686a..c3bad71e0d 100644
--- a/src/integrationTest/java/org/opensearch/test/framework/cluster/TestRestClient.java
+++ b/src/integrationTest/java/org/opensearch/test/framework/cluster/TestRestClient.java
@@ -50,6 +50,7 @@
 import org.apache.commons.io.IOUtils;
 import org.apache.http.Header;
 import org.apache.http.HttpEntity;
+import org.apache.http.HttpHeaders;
 import org.apache.http.NameValuePair;
 import org.apache.http.client.config.RequestConfig;
 import org.apache.http.client.methods.CloseableHttpResponse;
@@ -78,6 +79,7 @@
 import static java.util.Objects.requireNonNull;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.notNullValue;
 
 /**
@@ -294,6 +296,24 @@ public HttpResponse(CloseableHttpResponse inner) throws IllegalStateException, I
             this.statusCode = inner.getStatusLine().getStatusCode();
             this.statusReason = inner.getStatusLine().getReasonPhrase();
             inner.close();
+
+            if (this.body.length() != 0) {
+                verifyContentType();
+            }
+        }
+
+        private void verifyContentType() {
+            final String contentType = this.getHeader(HttpHeaders.CONTENT_TYPE).getValue();
+            if (contentType.contains("application/json")) {
+                assertThat("Response body format was not json, body: " + body, body.charAt(0), equalTo('{'));
+            } else {
+                assertThat(
+                    "Response body format was json, whereas content-type was " + contentType + ", body: " + body,
+                    body.charAt(0),
+                    not(equalTo('{'))
+                );
+            }
+
         }
 
         public String getContentType() {
diff --git a/src/test/java/org/opensearch/security/test/helper/rest/RestHelper.java b/src/test/java/org/opensearch/security/test/helper/rest/RestHelper.java
index 065c72afeb..3c9bfd8842 100644
--- a/src/test/java/org/opensearch/security/test/helper/rest/RestHelper.java
+++ b/src/test/java/org/opensearch/security/test/helper/rest/RestHelper.java
@@ -76,6 +76,10 @@
 import org.opensearch.security.test.helper.cluster.ClusterInfo;
 import org.opensearch.security.test.helper.file.FileHelper;
 
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.not;
+
 public class RestHelper {
 
     protected final Logger log = LogManager.getLogger(RestHelper.class);
@@ -313,7 +317,29 @@ public HttpResponse(CloseableHttpResponse inner) throws IllegalStateException, I
             this.header = inner.getAllHeaders();
             this.statusCode = inner.getStatusLine().getStatusCode();
             this.statusReason = inner.getStatusLine().getReasonPhrase();
-            inner.close();
+
+            if (this.body.length() != 0) {
+                verifyBodyContentType();
+            }
+        }
+
+        private void verifyBodyContentType() {
+            final String contentType = this.getHeaders()
+                .stream()
+                .filter(h -> HttpHeaders.CONTENT_TYPE.equalsIgnoreCase(h.getName()))
+                .map(Header::getValue)
+                .findFirst()
+                .orElseThrow(() -> new RuntimeException("No content type found. Headers:\n" + getHeaders() + "\n\nBody:\n" + body));
+
+            if (contentType.contains("application/json")) {
+                assertThat("Response body format was not json, body: " + body, body.charAt(0), equalTo('{'));
+            } else {
+                assertThat(
+                    "Response body format was json, whereas content-type was " + contentType + ", body: " + body,
+                    body.charAt(0),
+                    not(equalTo('{'))
+                );
+            }
         }
 
         public String getContentType() {