diff --git a/muted-tests.yml b/muted-tests.yml
index 87fc87ad77099..8c01812012ad6 100644
--- a/muted-tests.yml
+++ b/muted-tests.yml
@@ -380,18 +380,6 @@ tests:
 - class: org.elasticsearch.xpack.esql.qa.mixed.EsqlClientYamlIT
   method: test {p0=esql/40_tsdb/TS Command grouping on text field}
   issue: https://github.com/elastic/elasticsearch/issues/142544
-- class: org.elasticsearch.index.IndexSettingsTests
-  method: testSyntheticIdBadVersion
-  issue: https://github.com/elastic/elasticsearch/issues/142508
-- class: org.elasticsearch.index.IndexSettingsTests
-  method: testSyntheticIdBadCodec
-  issue: https://github.com/elastic/elasticsearch/issues/142509
-- class: org.elasticsearch.index.IndexSettingsTests
-  method: testSyntheticIdBadMode
-  issue: https://github.com/elastic/elasticsearch/issues/142510
-- class: org.elasticsearch.index.IndexSettingsTests
-  method: testSyntheticIdCorrectSettings
-  issue: https://github.com/elastic/elasticsearch/issues/142507
 - class: org.elasticsearch.xpack.esql.datasources.GlobDiscoveryLocalTests
   method: testRecursiveDoubleStarAllFiles
   issue: https://github.com/elastic/elasticsearch/issues/142576
diff --git a/server/src/test/java/org/elasticsearch/index/IndexSettingsTests.java b/server/src/test/java/org/elasticsearch/index/IndexSettingsTests.java
index 550374e93963f..7b773f7cf15d7 100644
--- a/server/src/test/java/org/elasticsearch/index/IndexSettingsTests.java
+++ b/server/src/test/java/org/elasticsearch/index/IndexSettingsTests.java
@@ -931,6 +931,7 @@ public void testSame() {
     }
 
     public void testSyntheticIdCorrectSettings() {
+        assumeTrue("Test should only run with feature flag", IndexSettings.TSDB_SYNTHETIC_ID_FEATURE_FLAG);
         IndexVersion version = IndexVersionUtils.randomVersionBetween(
             IndexVersions.TIME_SERIES_USE_SYNTHETIC_ID_94,
             IndexVersion.current()
@@ -952,6 +953,7 @@ public void testSyntheticIdCorrectSettings() {
     }
 
     public void testSyntheticIdBadVersion() {
+        assumeTrue("Test should only run with feature flag", IndexSettings.TSDB_SYNTHETIC_ID_FEATURE_FLAG);
         IndexVersion badVersion = IndexVersionUtils.getPreviousVersion(IndexVersions.TIME_SERIES_USE_SYNTHETIC_ID_94);
         IndexMode mode = IndexMode.TIME_SERIES;
         String codec = CodecService.DEFAULT_CODEC;
@@ -980,6 +982,7 @@ public void testSyntheticIdBadVersion() {
     }
 
     public void testSyntheticIdBadCodec() {
+        assumeTrue("Test should only run with feature flag", IndexSettings.TSDB_SYNTHETIC_ID_FEATURE_FLAG);
         IndexVersion version = IndexVersionUtils.randomVersionBetween(
             IndexVersions.TIME_SERIES_USE_SYNTHETIC_ID_94,
             IndexVersion.current()
@@ -1017,6 +1020,7 @@ public void testSyntheticIdBadCodec() {
     }
 
     public void testSyntheticIdBadMode() {
+        assumeTrue("Test should only run with feature flag", IndexSettings.TSDB_SYNTHETIC_ID_FEATURE_FLAG);
         IndexVersion version = IndexVersionUtils.randomVersionBetween(
             IndexVersions.TIME_SERIES_USE_SYNTHETIC_ID_94,
             IndexVersion.current()