diff --git a/src/integrationTest/java/org/opensearch/security/DoNotFailOnForbiddenTests.java b/src/integrationTest/java/org/opensearch/security/DoNotFailOnForbiddenTests.java
index 456d1ebada..4aa6005beb 100644
--- a/src/integrationTest/java/org/opensearch/security/DoNotFailOnForbiddenTests.java
+++ b/src/integrationTest/java/org/opensearch/security/DoNotFailOnForbiddenTests.java
@@ -12,6 +12,7 @@
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -462,8 +463,9 @@ public void shouldPerformCatIndices_positive() throws IOException {
             Request getIndicesRequest = new Request("GET", "/_cat/indices");
             // High level client doesn't support _cat/_indices API
             Response getIndicesResponse = restHighLevelClient.getLowLevelClient().performRequest(getIndicesRequest);
-            List<String> indexes = new BufferedReader(new InputStreamReader(getIndicesResponse.getEntity().getContent())).lines()
-                .collect(Collectors.toList());
+            List<String> indexes = new BufferedReader(
+                new InputStreamReader(getIndicesResponse.getEntity().getContent(), StandardCharsets.UTF_8)
+            ).lines().collect(Collectors.toList());
 
             assertThat(indexes.size(), equalTo(1));
             assertThat(indexes.get(0), containsString("marvelous_songs"));
@@ -476,8 +478,9 @@ public void shouldPerformCatAliases_positive() throws IOException {
         try (RestHighLevelClient restHighLevelClient = cluster.getRestHighLevelClient(LIMITED_USER)) {
             Request getAliasesRequest = new Request("GET", "/_cat/aliases");
             Response getAliasesResponse = restHighLevelClient.getLowLevelClient().performRequest(getAliasesRequest);
-            List<String> aliases = new BufferedReader(new InputStreamReader(getAliasesResponse.getEntity().getContent())).lines()
-                .collect(Collectors.toList());
+            List<String> aliases = new BufferedReader(
+                new InputStreamReader(getAliasesResponse.getEntity().getContent(), StandardCharsets.UTF_8)
+            ).lines().collect(Collectors.toList());
 
             // Does not fail on forbidden, but alias response only contains index which user has access to
             assertThat(getAliasesResponse.getStatusLine().getStatusCode(), equalTo(200));
@@ -490,8 +493,9 @@ public void shouldPerformCatAliases_positive() throws IOException {
         try (RestHighLevelClient restHighLevelClient = cluster.getRestHighLevelClient(ADMIN_USER)) {
             Request getAliasesRequest = new Request("GET", "/_cat/aliases");
             Response getAliasesResponse = restHighLevelClient.getLowLevelClient().performRequest(getAliasesRequest);
-            List<String> aliases = new BufferedReader(new InputStreamReader(getAliasesResponse.getEntity().getContent())).lines()
-                .collect(Collectors.toList());
+            List<String> aliases = new BufferedReader(
+                new InputStreamReader(getAliasesResponse.getEntity().getContent(), StandardCharsets.UTF_8)
+            ).lines().collect(Collectors.toList());
 
             // Admin has access to all
             assertThat(getAliasesResponse.getStatusLine().getStatusCode(), equalTo(200));
diff --git a/src/test/java/org/opensearch/security/support/SafeSerializationUtilsTest.java b/src/test/java/org/opensearch/security/support/SafeSerializationUtilsTest.java
index f69d4e0291..187fd8b372 100644
--- a/src/test/java/org/opensearch/security/support/SafeSerializationUtilsTest.java
+++ b/src/test/java/org/opensearch/security/support/SafeSerializationUtilsTest.java
@@ -17,6 +17,7 @@
 import java.util.HashMap;
 import java.util.regex.Pattern;
 
+import org.junit.After;
 import org.junit.Test;
 
 import org.opensearch.security.auth.UserInjector;
@@ -35,6 +36,11 @@
 
 public class SafeSerializationUtilsTest {
 
+    @After
+    public void clearCache() {
+        SafeSerializationUtils.safeClassCache.clear();
+    }
+
     @Test
     public void testSafeClasses() {
         assertTrue(SafeSerializationUtils.isSafeClass(String.class));