diff --git a/CHANGES.txt b/CHANGES.txt
index 09d1733837..02233dd17e 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -349,6 +349,7 @@
 
 
 3.11.5
+ * Add flag to disable SASI indexes, and warnings on creation (CASSANDRA-14866)
 Merged from 3.0:
  * Improve `nodetool status -r` speed (CASSANDRA-14847)
  * Improve merkle tree size and time on heap (CASSANDRA-14096)
@@ -390,7 +391,7 @@ Merged from 3.0:
  * Fix static column order for SELECT * wildcard queries (CASSANDRA-14638)
  * sstableloader should use discovered broadcast address to connect intra-cluster (CASSANDRA-14522)
  * Fix reading columns with non-UTF names from schema (CASSANDRA-14468)
- Merged from 2.2:
+Merged from 2.2:
  * CircleCI docker image should bake in more dependencies (CASSANDRA-14985)
  * MigrationManager attempts to pull schema from different major version nodes (CASSANDRA-14928)
  * Returns null instead of NaN or Infinity in JSON strings (CASSANDRA-14377)
diff --git a/NEWS.txt b/NEWS.txt
index d9950e3997..ead28f0ac3 100644
--- a/NEWS.txt
+++ b/NEWS.txt
@@ -210,7 +210,11 @@ Upgrading
       See CASSANDRA-14358 for details.
 	- repair_session_space_in_mb setting has been added to cassandra.yaml to allow operators to reduce
 	  merkle tree size if repair is creating too much heap pressure. The repair_session_max_tree_depth
-	  setting added in 3.0.19 and 3.11.5 is deprecated in favor of this setting. See CASSANDRA-14096 
+	  setting added in 3.0.19 and 3.11.5 is deprecated in favor of this setting. See CASSANDRA-14096
+    - The flags 'enable_materialized_views' and 'enable_sasi_indexes' in cassandra.yaml
+      have been set as false by default. Operators should modify them to allow the
+      creation of new views and SASI indexes, the existing ones will continue working.
+      See CASSANDRA-14866 for details.
 
 Materialized Views
 -------------------
@@ -223,6 +227,17 @@ Materialized Views
      to be NOT NULL, and no base primary key columns get automatically included in view definition. You have to
      specify them explicitly now.
 
+3.11.5
+======
+
+Experimental features
+---------------------
+    - An 'enable_sasi_indexes' flag, true by default, has been added to cassandra.yaml to allow operators to prevent
+      the creation of new SASI indexes, which are considered experimental and are not recommended for production use.
+      (See https://www.mail-archive.com/dev@cassandra.apache.org/msg13582.html)
+    - The flags 'enable_sasi_indexes' and 'enable_materialized_views' have been grouped under an experimental features
+      section in cassandra.yaml.
+
 3.11.4
 ======
 
diff --git a/conf/cassandra.yaml b/conf/cassandra.yaml
index 78fb16290e..ca854ca65e 100644
--- a/conf/cassandra.yaml
+++ b/conf/cassandra.yaml
@@ -1075,14 +1075,6 @@ enable_user_defined_functions: false
 # This option has no effect, if enable_user_defined_functions is false.
 enable_scripted_user_defined_functions: false
 
-# Enables materialized view creation on this node.
-# Materialized views are considered experimental and are not recommended for production use.
-enable_materialized_views: true
-
-# Enables creation of transiently replicated keyspaces on this node.
-# Transient replication is experimental and is not recommended for production use.
-#enable_transient_replication: true
-
 # The default Windows kernel timer and scheduling resolution is 15.6ms for power conservation.
 # Lowering this value on Windows can provide much tighter latency and better throughput, however
 # some virtualized environments may see a negative performance impact from changing this setting
@@ -1299,3 +1291,18 @@ repaired_data_tracking_for_partition_reads_enabled: false
 # mismatches are less actionable than confirmed ones.
 report_unconfirmed_repaired_data_mismatches: false
 
+#########################
+# EXPERIMENTAL FEATURES #
+#########################
+
+# Enables materialized view creation on this node.
+# Materialized views are considered experimental and are not recommended for production use.
+enable_materialized_views: false
+
+# Enables SASI index creation on this node.
+# SASI indexes are considered experimental and are not recommended for production use.
+enable_sasi_indexes: false
+
+# Enables creation of transiently replicated keyspaces on this node.
+# Transient replication is experimental and is not recommended for production use.
+enable_transient_replication: false
\ No newline at end of file
diff --git a/src/java/org/apache/cassandra/config/Config.java b/src/java/org/apache/cassandra/config/Config.java
index a95db233d0..04ac6083f5 100644
--- a/src/java/org/apache/cassandra/config/Config.java
+++ b/src/java/org/apache/cassandra/config/Config.java
@@ -354,10 +354,12 @@ public class Config
     public boolean enable_user_defined_functions = false;
     public boolean enable_scripted_user_defined_functions = false;
 
-    public boolean enable_materialized_views = true;
+    public boolean enable_materialized_views = false;
 
     public boolean enable_transient_replication = false;
 
+    public boolean enable_sasi_indexes = false;
+
     /**
      * Optionally disable asynchronous UDF execution.
      * Disabling asynchronous UDF execution also implicitly disables the security-manager!
diff --git a/src/java/org/apache/cassandra/config/DatabaseDescriptor.java b/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
index 3f80d7111d..e5fe77242e 100644
--- a/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
+++ b/src/java/org/apache/cassandra/config/DatabaseDescriptor.java
@@ -2547,11 +2547,26 @@ public class DatabaseDescriptor
         conf.user_defined_function_warn_timeout = userDefinedFunctionWarnTimeout;
     }
 
-    public static boolean enableMaterializedViews()
+    public static boolean getEnableMaterializedViews()
     {
         return conf.enable_materialized_views;
     }
 
+    public static void setEnableMaterializedViews(boolean enableMaterializedViews)
+    {
+        conf.enable_materialized_views = enableMaterializedViews;
+    }
+
+    public static boolean getEnableSASIIndexes()
+    {
+        return conf.enable_sasi_indexes;
+    }
+
+    public static void setEnableSASIIndexes(boolean enableSASIIndexes)
+    {
+        conf.enable_sasi_indexes = enableSASIIndexes;
+    }
+
     public static boolean isTransientReplicationEnabled()
     {
         return conf.enable_transient_replication;
diff --git a/src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java b/src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java
index dbca160e3d..18c6511f0c 100644
--- a/src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java
+++ b/src/java/org/apache/cassandra/cql3/statements/schema/CreateIndexStatement.java
@@ -19,11 +19,13 @@ package org.apache.cassandra.cql3.statements.schema;
 
 import java.util.*;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 
 import org.apache.cassandra.audit.AuditLogContext;
 import org.apache.cassandra.audit.AuditLogEntryType;
 import org.apache.cassandra.auth.Permission;
+import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.cql3.CQLStatement;
 import org.apache.cassandra.cql3.ColumnIdentifier;
 import org.apache.cassandra.cql3.QualifiedName;
@@ -31,6 +33,7 @@ import org.apache.cassandra.cql3.statements.schema.IndexTarget.Type;
 import org.apache.cassandra.db.Keyspace;
 import org.apache.cassandra.db.marshal.MapType;
 import org.apache.cassandra.exceptions.InvalidRequestException;
+import org.apache.cassandra.index.sasi.SASIIndex;
 import org.apache.cassandra.schema.*;
 import org.apache.cassandra.schema.Keyspaces.KeyspacesDiff;
 import org.apache.cassandra.service.ClientState;
@@ -68,6 +71,9 @@ public final class CreateIndexStatement extends AlterSchemaStatement
     {
         attrs.validate();
 
+        if (attrs.isCustom && attrs.customClass.equals(SASIIndex.class.getName()) && !DatabaseDescriptor.getEnableSASIIndexes())
+            throw new InvalidRequestException("SASI indexes are disabled. Enable in cassandra.yaml to use.");
+
         KeyspaceMetadata keyspace = schema.getNullable(keyspaceName);
         if (null == keyspace)
             throw ire("Keyspace '%s' doesn't exist", keyspaceName);
@@ -135,6 +141,15 @@ public final class CreateIndexStatement extends AlterSchemaStatement
         return schema.withAddedOrUpdated(keyspace.withSwapped(keyspace.tables.withSwapped(newTable)));
     }
 
+    @Override
+    Set<String> clientWarnings(KeyspacesDiff diff)
+    {
+        if (attrs.isCustom && attrs.customClass.equals(SASIIndex.class.getName()))
+            return ImmutableSet.of(SASIIndex.USAGE_WARNING);
+
+        return ImmutableSet.of();
+    }
+
     private void validateIndexTarget(TableMetadata table, IndexTarget target)
     {
         ColumnMetadata column = table.getColumn(target.column);
diff --git a/src/java/org/apache/cassandra/cql3/statements/schema/CreateViewStatement.java b/src/java/org/apache/cassandra/cql3/statements/schema/CreateViewStatement.java
index bf6bcff53b..7e51eb2ad8 100644
--- a/src/java/org/apache/cassandra/cql3/statements/schema/CreateViewStatement.java
+++ b/src/java/org/apache/cassandra/cql3/statements/schema/CreateViewStatement.java
@@ -31,9 +31,9 @@ import org.apache.cassandra.cql3.restrictions.StatementRestrictions;
 import org.apache.cassandra.cql3.selection.RawSelector;
 import org.apache.cassandra.cql3.selection.Selectable;
 import org.apache.cassandra.cql3.statements.StatementType;
-import org.apache.cassandra.db.Keyspace;
 import org.apache.cassandra.db.marshal.AbstractType;
 import org.apache.cassandra.db.marshal.ReversedType;
+import org.apache.cassandra.db.view.View;
 import org.apache.cassandra.exceptions.AlreadyExistsException;
 import org.apache.cassandra.exceptions.InvalidRequestException;
 import org.apache.cassandra.schema.*;
@@ -98,7 +98,7 @@ public final class CreateViewStatement extends AlterSchemaStatement
 
     public Keyspaces apply(Keyspaces schema)
     {
-        if (!DatabaseDescriptor.enableMaterializedViews())
+        if (!DatabaseDescriptor.getEnableMaterializedViews())
             throw ire("Materialized views are disabled. Enable in cassandra.yaml to use.");
 
         /*
@@ -337,7 +337,7 @@ public final class CreateViewStatement extends AlterSchemaStatement
     @Override
     Set<String> clientWarnings(KeyspacesDiff diff)
     {
-        return ImmutableSet.of("Materialized views are experimental and are not recommended for production use.");
+        return ImmutableSet.of(View.USAGE_WARNING);
     }
 
     @Override
diff --git a/src/java/org/apache/cassandra/db/view/View.java b/src/java/org/apache/cassandra/db/view/View.java
index 40f1b84859..af470ffa86 100644
--- a/src/java/org/apache/cassandra/db/view/View.java
+++ b/src/java/org/apache/cassandra/db/view/View.java
@@ -45,6 +45,8 @@ import org.slf4j.LoggerFactory;
  */
 public class View
 {
+    public final static String USAGE_WARNING = "Materialized views are experimental and are not recommended for production use.";
+
     private static final Logger logger = LoggerFactory.getLogger(View.class);
 
     public final String name;
diff --git a/src/java/org/apache/cassandra/index/sasi/SASIIndex.java b/src/java/org/apache/cassandra/index/sasi/SASIIndex.java
index 3ffcb6ebf7..19c09cc516 100644
--- a/src/java/org/apache/cassandra/index/sasi/SASIIndex.java
+++ b/src/java/org/apache/cassandra/index/sasi/SASIIndex.java
@@ -62,6 +62,8 @@ import org.apache.cassandra.utils.concurrent.OpOrder;
 
 public class SASIIndex implements Index, INotificationConsumer
 {
+    public final static String USAGE_WARNING = "SASI indexes are experimental and are not recommended for production use.";
+
     private static class SASIIndexBuildingSupport implements IndexBuildingSupport
     {
         public SecondaryIndexBuilder getIndexBuildTask(ColumnFamilyStore cfs,
diff --git a/test/conf/cassandra-murmur.yaml b/test/conf/cassandra-murmur.yaml
index a8288d0688..e933837ccd 100644
--- a/test/conf/cassandra-murmur.yaml
+++ b/test/conf/cassandra-murmur.yaml
@@ -40,3 +40,5 @@ row_cache_class_name: org.apache.cassandra.cache.OHCProvider
 row_cache_size_in_mb: 16
 enable_user_defined_functions: true
 enable_scripted_user_defined_functions: true
+enable_sasi_indexes: true
+enable_materialized_views: true
diff --git a/test/conf/cassandra.yaml b/test/conf/cassandra.yaml
index 3c096372ee..d94c478b9a 100644
--- a/test/conf/cassandra.yaml
+++ b/test/conf/cassandra.yaml
@@ -48,3 +48,5 @@ prepared_statements_cache_size_mb: 1
 corrupted_tombstone_strategy: exception
 stream_entire_sstables: true
 stream_throughput_outbound_megabits_per_sec: 200000000
+enable_sasi_indexes: true
+enable_materialized_views: true
diff --git a/test/unit/org/apache/cassandra/cql3/ViewTest.java b/test/unit/org/apache/cassandra/cql3/ViewTest.java
index 4f99d0340f..02fa19effa 100644
--- a/test/unit/org/apache/cassandra/cql3/ViewTest.java
+++ b/test/unit/org/apache/cassandra/cql3/ViewTest.java
@@ -39,12 +39,15 @@ import com.datastax.driver.core.exceptions.InvalidQueryException;
 import org.apache.cassandra.concurrent.SEPExecutor;
 import org.apache.cassandra.concurrent.Stage;
 import org.apache.cassandra.concurrent.StageManager;
+import org.apache.cassandra.config.DatabaseDescriptor;
+import org.apache.cassandra.db.view.View;
 import org.apache.cassandra.schema.TableMetadata;
 import org.apache.cassandra.schema.ColumnMetadata;
 import org.apache.cassandra.db.ColumnFamilyStore;
 import org.apache.cassandra.db.Keyspace;
 import org.apache.cassandra.db.SystemKeyspace;
 import org.apache.cassandra.db.compaction.CompactionManager;
+import org.apache.cassandra.service.ClientWarn;
 import org.apache.cassandra.transport.ProtocolVersion;
 import org.apache.cassandra.utils.FBUtilities;
 
@@ -1392,4 +1395,52 @@ public class ViewTest extends CQLTester
             testViewBuilderResume(i);
         }
     }
+
+    /**
+     * Tests that a client warning is issued on materialized view creation.
+     */
+    @Test
+    public void testClientWarningOnCreate() throws Throwable
+    {
+        createTable("CREATE TABLE %s (k int PRIMARY KEY, v int)");
+
+        ClientWarn.instance.captureWarnings();
+        String viewName = keyspace() + ".warning_view";
+        execute("CREATE MATERIALIZED VIEW " + viewName +
+                " AS SELECT * FROM %s WHERE k IS NOT NULL AND v IS NOT NULL PRIMARY KEY (v, k)");
+        views.add(viewName);
+        List<String> warnings = ClientWarn.instance.getWarnings();
+
+        Assert.assertNotNull(warnings);
+        Assert.assertEquals(1, warnings.size());
+        Assert.assertEquals(View.USAGE_WARNING, warnings.get(0));
+    }
+
+    /**
+     * Tests the configuration flag to disable materialized views.
+     */
+    @Test
+    public void testDisableMaterializedViews() throws Throwable
+    {
+        createTable("CREATE TABLE %s (k int PRIMARY KEY, v int)");
+
+        executeNet(protocolVersion, "USE " + keyspace());
+
+        boolean enableMaterializedViews = DatabaseDescriptor.getEnableMaterializedViews();
+        try
+        {
+            DatabaseDescriptor.setEnableMaterializedViews(false);
+            createView("view1", "CREATE MATERIALIZED VIEW %s AS SELECT v FROM %%s WHERE k IS NOT NULL AND v IS NOT NULL PRIMARY KEY (v, k)");
+            Assert.fail("Should not be able to create a materialized view if they are disabled");
+        }
+        catch (Throwable e)
+        {
+            Assert.assertTrue(e instanceof InvalidQueryException);
+            Assert.assertTrue(e.getMessage().contains("Materialized views are disabled"));
+        }
+        finally
+        {
+            DatabaseDescriptor.setEnableMaterializedViews(enableMaterializedViews);
+        }
+    }
 }
\ No newline at end of file
diff --git a/test/unit/org/apache/cassandra/index/sasi/SASICQLTest.java b/test/unit/org/apache/cassandra/index/sasi/SASICQLTest.java
index f46e0b80a1..f78d35e058 100644
--- a/test/unit/org/apache/cassandra/index/sasi/SASICQLTest.java
+++ b/test/unit/org/apache/cassandra/index/sasi/SASICQLTest.java
@@ -28,7 +28,11 @@ import com.datastax.driver.core.Row;
 import com.datastax.driver.core.Session;
 import com.datastax.driver.core.SimpleStatement;
 import org.junit.Assert;
+
+import org.apache.cassandra.config.DatabaseDescriptor;
 import org.apache.cassandra.cql3.CQLTester;
+import org.apache.cassandra.exceptions.InvalidRequestException;
+import org.apache.cassandra.service.ClientWarn;
 
 public class SASICQLTest extends CQLTester
 {
@@ -78,4 +82,49 @@ public class SASICQLTest extends CQLTester
             Assert.assertEquals(20, rs.size());
         }
     }
+
+    /**
+     * Tests that a client warning is issued on SASI index creation.
+     */
+    @Test
+    public void testClientWarningOnCreate()
+    {
+        createTable("CREATE TABLE %s (k int PRIMARY KEY, v int)");
+
+        ClientWarn.instance.captureWarnings();
+        createIndex("CREATE CUSTOM INDEX ON %s (v) USING 'org.apache.cassandra.index.sasi.SASIIndex'");
+        List<String> warnings = ClientWarn.instance.getWarnings();
+
+        Assert.assertNotNull(warnings);
+        Assert.assertEquals(1, warnings.size());
+        Assert.assertEquals(SASIIndex.USAGE_WARNING, warnings.get(0));
+    }
+
+    /**
+     * Tests the configuration flag to disable SASI indexes.
+     */
+    @Test
+    public void testDisableSASIIndexes()
+    {
+        createTable("CREATE TABLE %s (k int PRIMARY KEY, v int)");
+
+        boolean enableSASIIndexes = DatabaseDescriptor.getEnableSASIIndexes();
+        try
+        {
+            DatabaseDescriptor.setEnableSASIIndexes(false);
+            createIndex("CREATE CUSTOM INDEX ON %s (v) USING 'org.apache.cassandra.index.sasi.SASIIndex'");
+            Assert.fail("Should not be able to create a SASI index if they are disabled");
+        }
+        catch (RuntimeException e)
+        {
+            Throwable cause = e.getCause();
+            Assert.assertNotNull(cause);
+            Assert.assertTrue(cause instanceof InvalidRequestException);
+            Assert.assertTrue(cause.getMessage().contains("SASI indexes are disabled"));
+        }
+        finally
+        {
+            DatabaseDescriptor.setEnableSASIIndexes(enableSASIIndexes);
+        }
+    }
 }