diff --git a/modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/250_data_stream_mappings.yml b/modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/250_data_stream_mappings.yml
index c0fef3e6bae07..5dc465d05a80a 100644
--- a/modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/250_data_stream_mappings.yml
+++ b/modules/data-streams/src/yamlRestTest/resources/rest-api-spec/test/data_stream/250_data_stream_mappings.yml
@@ -34,7 +34,7 @@ setup:
         name: my-data-stream-1
   - match: { data_streams.0.name: my-data-stream-1 }
   - match: { data_streams.0.mappings: {} }
-  - length: { data_streams.0.effective_mappings._doc.properties: 2 }
+  - length: { data_streams.0.effective_mappings.properties: 2 }
 
   - do:
       indices.get_data_stream:
@@ -56,7 +56,7 @@ setup:
   - match: { data_streams.0.name: my-data-stream-1 }
   - match: { data_streams.0.applied_to_data_stream: true }
   - match: { data_streams.0.mappings.properties.name.type: "keyword" }
-  - match: { data_streams.0.effective_mappings._doc.properties.name.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.name.type: "keyword" }
 
   - do:
       indices.rollover:
@@ -71,9 +71,9 @@ setup:
       indices.get_data_stream_mappings:
         name: my-data-stream-1
   - match: { data_streams.0.name: my-data-stream-1 }
-  - length: { data_streams.0.effective_mappings._doc.properties: 3 }
+  - length: { data_streams.0.effective_mappings.properties: 3 }
   - match: { data_streams.0.mappings.properties.name.type: "keyword" }
-  - match: { data_streams.0.effective_mappings._doc.properties.name.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.name.type: "keyword" }
 
   - do:
       indices.get_data_stream:
@@ -149,9 +149,9 @@ setup:
   - match: { data_streams.0.mappings.properties.field1.type: "text" }
   - match: { data_streams.0.mappings.properties.field2: null }
   - match: { data_streams.0.mappings.properties.field3.type: "text" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field1.type: "text" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field2.type: "keyword" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field3.type: "text" }
+  - match: { data_streams.0.effective_mappings.properties.field1.type: "text" }
+  - match: { data_streams.0.effective_mappings.properties.field2.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.field3.type: "text" }
 
   - do:
       cluster.put_component_template:
@@ -180,10 +180,10 @@ setup:
       indices.get_data_stream_mappings:
         name: my-component-only-data-stream-1
   - match: { data_streams.0.name: my-component-only-data-stream-1 }
-  - length: { data_streams.0.effective_mappings._doc.properties: 5 }
+  - length: { data_streams.0.effective_mappings.properties: 5 }
   - match: { data_streams.0.mappings.properties.field1.type: "text" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field3.type: "text" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field4.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.field3.type: "text" }
+  - match: { data_streams.0.effective_mappings.properties.field4.type: "keyword" }
 
   - do:
       indices.get_data_stream:
@@ -212,7 +212,7 @@ setup:
   - match: { data_streams.0.name: my-component-only-data-stream-1 }
   - match: { data_streams.0.applied_to_data_stream: true }
   - match: { data_streams.0.mappings null }
-  - match: { data_streams.0.effective_mappings._doc.properties.field1.type: "keyword" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field2.type: "keyword" }
-  - match: { data_streams.0.effective_mappings._doc.properties.field3: null }
-  - match: { data_streams.0.effective_mappings._doc.properties.field4.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.field1.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.field2.type: "keyword" }
+  - match: { data_streams.0.effective_mappings.properties.field3: null }
+  - match: { data_streams.0.effective_mappings.properties.field4.type: "keyword" }
diff --git a/server/src/main/java/org/elasticsearch/cluster/metadata/DataStream.java b/server/src/main/java/org/elasticsearch/cluster/metadata/DataStream.java
index fddcc838e3a11..0a7b328f67823 100644
--- a/server/src/main/java/org/elasticsearch/cluster/metadata/DataStream.java
+++ b/server/src/main/java/org/elasticsearch/cluster/metadata/DataStream.java
@@ -499,7 +499,7 @@ public static CompressedXContent getEffectiveMappings(
             xContentRegistry,
             writeIndex.getName()
         );
-        return indicesService.withTempIndexService(projectMetadata.index(writeIndex), indexService -> {
+        CompressedXContent mergedMapping = indicesService.withTempIndexService(projectMetadata.index(writeIndex), indexService -> {
             MapperService mapperService = indexService.mapperService();
             DocumentMapper documentMapper = mapperService.merge(
                 MapperService.SINGLE_MAPPING_NAME,
@@ -508,6 +508,15 @@ public static CompressedXContent getEffectiveMappings(
             );
             return documentMapper.mappingSource();
         });
+
+        // Strip the _doc wrapper from the merged mapping to match the API specification
+        Map<String, Object> mergedMappingMap = XContentHelper.convertToMap(mergedMapping.uncompressed(), true, XContentType.JSON).v2();
+        if (mergedMappingMap.containsKey(MapperService.SINGLE_MAPPING_NAME)) {
+            mergedMapping = ComposableIndexTemplate.convertMappingMapToXContent(
+                (Map<String, ?>) mergedMappingMap.get(MapperService.SINGLE_MAPPING_NAME)
+            );
+        }
+        return mergedMapping;
     }
 
     private ComposableIndexTemplate getMatchingIndexTemplate(ProjectMetadata projectMetadata) {