diff --git a/src/main/java/org/opensearch/neuralsearch/plugin/NeuralSearch.java b/src/main/java/org/opensearch/neuralsearch/plugin/NeuralSearch.java
index a47436fa8..a796b72d7 100644
--- a/src/main/java/org/opensearch/neuralsearch/plugin/NeuralSearch.java
+++ b/src/main/java/org/opensearch/neuralsearch/plugin/NeuralSearch.java
@@ -98,6 +98,8 @@ public Map<String, Processor.Factory> getProcessors(Processor.Parameters paramet
     @Override
     public Optional<QueryPhaseSearcher> getQueryPhaseSearcher() {
         if (FeatureFlags.isEnabled(NEURAL_SEARCH_HYBRID_SEARCH_DISABLED.getValue())) {
+            // we want feature be disabled by default due to risk of colliding and breaking concurrent search in core
+            // but we only can set "true" values by default due to implementation limitations in core.
             return Optional.empty();
         }
         return Optional.of(new HybridQueryPhaseSearcher());
diff --git a/src/test/java/org/opensearch/neuralsearch/TestUtils.java b/src/test/java/org/opensearch/neuralsearch/TestUtils.java
index 4f0c5129d..257545132 100644
--- a/src/test/java/org/opensearch/neuralsearch/TestUtils.java
+++ b/src/test/java/org/opensearch/neuralsearch/TestUtils.java
@@ -9,8 +9,8 @@
 
 import java.util.Map;
 
-import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.xcontent.XContentHelper;
+import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.XContentBuilder;
 
 public class TestUtils {
diff --git a/src/test/java/org/opensearch/neuralsearch/common/BaseNeuralSearchIT.java b/src/test/java/org/opensearch/neuralsearch/common/BaseNeuralSearchIT.java
index 59414b49b..e1f907a5c 100644
--- a/src/test/java/org/opensearch/neuralsearch/common/BaseNeuralSearchIT.java
+++ b/src/test/java/org/opensearch/neuralsearch/common/BaseNeuralSearchIT.java
@@ -40,12 +40,12 @@
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.common.xcontent.XContentHelper;
 import org.opensearch.common.xcontent.XContentType;
+import org.opensearch.core.rest.RestStatus;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.query.QueryBuilder;
 import org.opensearch.knn.index.SpaceType;
 import org.opensearch.neuralsearch.OpenSearchSecureRestTestCase;
-import org.opensearch.rest.RestStatus;
 
 import com.google.common.collect.ImmutableList;
 
diff --git a/src/test/java/org/opensearch/neuralsearch/query/HybridQueryBuilderTests.java b/src/test/java/org/opensearch/neuralsearch/query/HybridQueryBuilderTests.java
index b8f253c84..49d1ba974 100644
--- a/src/test/java/org/opensearch/neuralsearch/query/HybridQueryBuilderTests.java
+++ b/src/test/java/org/opensearch/neuralsearch/query/HybridQueryBuilderTests.java
@@ -28,19 +28,19 @@
 import org.apache.lucene.search.MatchNoDocsQuery;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
-import org.opensearch.common.ParsingException;
-import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.io.stream.BytesStreamOutput;
-import org.opensearch.common.io.stream.FilterStreamInput;
-import org.opensearch.common.io.stream.NamedWriteableAwareStreamInput;
-import org.opensearch.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.ParseField;
+import org.opensearch.core.common.ParsingException;
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.io.stream.FilterStreamInput;
+import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
+import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
+import org.opensearch.core.index.Index;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.core.xcontent.XContentParser;
-import org.opensearch.index.Index;
 import org.opensearch.index.mapper.TextFieldMapper;
 import org.opensearch.index.query.MatchAllQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
diff --git a/src/test/java/org/opensearch/neuralsearch/query/HybridQueryTests.java b/src/test/java/org/opensearch/neuralsearch/query/HybridQueryTests.java
index 21287ccb7..4d24c2049 100644
--- a/src/test/java/org/opensearch/neuralsearch/query/HybridQueryTests.java
+++ b/src/test/java/org/opensearch/neuralsearch/query/HybridQueryTests.java
@@ -34,7 +34,7 @@
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.tests.analysis.MockAnalyzer;
 import org.apache.lucene.tests.search.QueryUtils;
-import org.opensearch.index.Index;
+import org.opensearch.core.index.Index;
 import org.opensearch.index.mapper.TextFieldMapper;
 import org.opensearch.index.query.BoolQueryBuilder;
 import org.opensearch.index.query.QueryBuilders;
diff --git a/src/test/java/org/opensearch/neuralsearch/query/NeuralQueryBuilderTests.java b/src/test/java/org/opensearch/neuralsearch/query/NeuralQueryBuilderTests.java
index 7f48e61f9..dda4713b9 100644
--- a/src/test/java/org/opensearch/neuralsearch/query/NeuralQueryBuilderTests.java
+++ b/src/test/java/org/opensearch/neuralsearch/query/NeuralQueryBuilderTests.java
@@ -31,14 +31,14 @@
 
 import org.opensearch.action.ActionListener;
 import org.opensearch.client.Client;
-import org.opensearch.common.ParsingException;
-import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.io.stream.BytesStreamOutput;
-import org.opensearch.common.io.stream.FilterStreamInput;
-import org.opensearch.common.io.stream.NamedWriteableAwareStreamInput;
-import org.opensearch.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.common.xcontent.XContentFactory;
 import org.opensearch.core.ParseField;
+import org.opensearch.core.common.ParsingException;
+import org.opensearch.core.common.bytes.BytesReference;
+import org.opensearch.core.common.io.stream.FilterStreamInput;
+import org.opensearch.core.common.io.stream.NamedWriteableAwareStreamInput;
+import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
 import org.opensearch.core.xcontent.NamedXContentRegistry;
 import org.opensearch.core.xcontent.ToXContent;
 import org.opensearch.core.xcontent.XContentBuilder;
diff --git a/src/test/java/org/opensearch/neuralsearch/query/OpenSearchQueryTestCase.java b/src/test/java/org/opensearch/neuralsearch/query/OpenSearchQueryTestCase.java
index e954004c7..0ce8e8fd1 100644
--- a/src/test/java/org/opensearch/neuralsearch/query/OpenSearchQueryTestCase.java
+++ b/src/test/java/org/opensearch/neuralsearch/query/OpenSearchQueryTestCase.java
@@ -28,10 +28,10 @@
 import org.opensearch.Version;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.common.CheckedConsumer;
-import org.opensearch.common.bytes.BytesReference;
 import org.opensearch.common.compress.CompressedXContent;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.xcontent.XContentFactory;
+import org.opensearch.core.common.bytes.BytesReference;
 import org.opensearch.core.xcontent.XContentBuilder;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.analysis.AnalyzerScope;
diff --git a/src/test/java/org/opensearch/neuralsearch/search/query/HybridQueryPhaseSearcherTests.java b/src/test/java/org/opensearch/neuralsearch/search/query/HybridQueryPhaseSearcherTests.java
index 14e2064d6..8c078ec88 100644
--- a/src/test/java/org/opensearch/neuralsearch/search/query/HybridQueryPhaseSearcherTests.java
+++ b/src/test/java/org/opensearch/neuralsearch/search/query/HybridQueryPhaseSearcherTests.java
@@ -36,7 +36,8 @@
 import org.apache.lucene.tests.analysis.MockAnalyzer;
 import org.opensearch.action.OriginalIndices;
 import org.opensearch.common.lucene.search.TopDocsAndMaxScore;
-import org.opensearch.index.Index;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.index.mapper.TextFieldMapper;
 import org.opensearch.index.query.MatchAllQueryBuilder;
 import org.opensearch.index.query.QueryBuilder;
@@ -44,7 +45,6 @@
 import org.opensearch.index.query.QueryShardContext;
 import org.opensearch.index.query.TermQueryBuilder;
 import org.opensearch.index.shard.IndexShard;
-import org.opensearch.index.shard.ShardId;
 import org.opensearch.knn.index.mapper.KNNVectorFieldMapper;
 import org.opensearch.neuralsearch.query.HybridQueryBuilder;
 import org.opensearch.neuralsearch.query.OpenSearchQueryTestCase;