diff --git a/x-pack/plugin/src/main/java/org/elasticsearch/xpack/ccr/action/bulk/TransportBulkShardOperationsAction.java b/x-pack/plugin/src/main/java/org/elasticsearch/xpack/ccr/action/bulk/TransportBulkShardOperationsAction.java
index b794ad10eac..7d92c5fc938 100644
--- a/x-pack/plugin/src/main/java/org/elasticsearch/xpack/ccr/action/bulk/TransportBulkShardOperationsAction.java
+++ b/x-pack/plugin/src/main/java/org/elasticsearch/xpack/ccr/action/bulk/TransportBulkShardOperationsAction.java
@@ -13,6 +13,7 @@ import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.engine.Engine;
+import org.elasticsearch.index.mapper.MapperException;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.translog.Translog;
 import org.elasticsearch.indices.IndicesService;
@@ -67,7 +68,10 @@ public class TransportBulkShardOperationsAction
             final BulkShardOperationsRequest request, final IndexShard shard, final Engine.Operation.Origin origin) throws IOException {
         Translog.Location location = null;
         for (final Translog.Operation operation : request.getOperations()) {
-            final Engine.Result result = shard.applyTranslogOperation(operation, origin, m -> {});
+            final Engine.Result result = shard.applyTranslogOperation(operation, origin, m -> {
+                // TODO: Figure out how to deal best with dynamic mapping updates from the leader side:
+                throw new MapperException("dynamic mapping updates are not allowed in follow shards [" + operation + "]");
+            });
             assert result.getSeqNo() == operation.seqNo();
             assert result.hasFailure() == false;
             location = locationToSync(location, result.getTranslogLocation());