diff --git a/server/src/main/java/org/elasticsearch/index/codec/PerFieldFormatSupplier.java b/server/src/main/java/org/elasticsearch/index/codec/PerFieldFormatSupplier.java
index b88ae698134b9..88dd2aea440a3 100644
--- a/server/src/main/java/org/elasticsearch/index/codec/PerFieldFormatSupplier.java
+++ b/server/src/main/java/org/elasticsearch/index/codec/PerFieldFormatSupplier.java
@@ -50,8 +50,10 @@ public PerFieldFormatSupplier(MapperService mapperService, BigArrays bigArrays)
         this.mapperService = mapperService;
         this.bloomFilterPostingsFormat = new ES87BloomFilterPostingsFormat(bigArrays, this::internalGetPostingsFormatForField);
 
+        // TODO: temporarily disable feature flag for a few days to see effect in benchmarks
+        boolean useDefaultLucenePostingsFormat = USE_DEFAULT_LUCENE_POSTINGS_FORMAT.isEnabled() && false;
         if (mapperService != null
-            && USE_DEFAULT_LUCENE_POSTINGS_FORMAT.isEnabled()
+            && useDefaultLucenePostingsFormat
             && mapperService.getIndexSettings().getIndexVersionCreated().onOrAfter(IndexVersions.USE_LUCENE101_POSTINGS_FORMAT)
             && mapperService.getIndexSettings().getMode() == IndexMode.STANDARD) {
             defaultPostingsFormat = Elasticsearch900Lucene101Codec.DEFAULT_POSTINGS_FORMAT;
diff --git a/server/src/test/java/org/elasticsearch/index/codec/PerFieldMapperCodecTests.java b/server/src/test/java/org/elasticsearch/index/codec/PerFieldMapperCodecTests.java
index dcd43326dcbb1..0e6b51ec6d3a5 100644
--- a/server/src/test/java/org/elasticsearch/index/codec/PerFieldMapperCodecTests.java
+++ b/server/src/test/java/org/elasticsearch/index/codec/PerFieldMapperCodecTests.java
@@ -10,7 +10,6 @@
 package org.elasticsearch.index.codec;
 
 import org.apache.lucene.codecs.PostingsFormat;
-import org.apache.lucene.codecs.lucene101.Lucene101PostingsFormat;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;
@@ -94,8 +93,7 @@ public void testUseBloomFilter() throws IOException {
         assertThat(perFieldMapperCodec.getPostingsFormatForField("_id"), instanceOf(ES87BloomFilterPostingsFormat.class));
         assertThat(perFieldMapperCodec.useBloomFilter("another_field"), is(false));
 
-        Class<? extends PostingsFormat> expectedPostingsFormat = PerFieldFormatSupplier.USE_DEFAULT_LUCENE_POSTINGS_FORMAT.isEnabled()
-            && timeSeries == false ? Lucene101PostingsFormat.class : ES812PostingsFormat.class;
+        Class<? extends PostingsFormat> expectedPostingsFormat = ES812PostingsFormat.class;
         assertThat(perFieldMapperCodec.getPostingsFormatForField("another_field"), instanceOf(expectedPostingsFormat));
     }
 
@@ -110,9 +108,7 @@ public void testUseBloomFilterWithTimestampFieldEnabled() throws IOException {
     public void testUseBloomFilterWithTimestampFieldEnabled_noTimeSeriesMode() throws IOException {
         PerFieldFormatSupplier perFieldMapperCodec = createFormatSupplier(true, false, false);
         assertThat(perFieldMapperCodec.useBloomFilter("_id"), is(false));
-        Class<? extends PostingsFormat> expectedPostingsFormat = PerFieldFormatSupplier.USE_DEFAULT_LUCENE_POSTINGS_FORMAT.isEnabled()
-            ? Lucene101PostingsFormat.class
-            : ES812PostingsFormat.class;
+        Class<? extends PostingsFormat> expectedPostingsFormat = ES812PostingsFormat.class;
         assertThat(perFieldMapperCodec.getPostingsFormatForField("_id"), instanceOf(expectedPostingsFormat));
     }