diff --git a/artifact/artifact/v1alpha/chunk.proto b/artifact/artifact/v1alpha/chunk.proto
index 0ecaa9e4..d79c8c35 100644
--- a/artifact/artifact/v1alpha/chunk.proto
+++ b/artifact/artifact/v1alpha/chunk.proto
@@ -89,8 +89,8 @@ message SimilarityChunksSearchRequest {
   string catalog_id = 2;
   // text prompt
   string text_prompt = 3;
-  // topk
-  uint32 topk = 4;
+  // top k
+  uint32 top_k = 4;
 }
 
 // Similar chunnk search response
diff --git a/openapiv2/artifact/service.swagger.yaml b/openapiv2/artifact/service.swagger.yaml
index ac8db3e0..d3dd9665 100644
--- a/openapiv2/artifact/service.swagger.yaml
+++ b/openapiv2/artifact/service.swagger.yaml
@@ -500,10 +500,10 @@ definitions:
       textPrompt:
         type: string
         title: text prompt
-      topk:
+      topK:
         type: integer
         format: int64
-        title: topk
+        title: top k
     title: Similar chunnk search request
   ArtifactPublicServiceUpdateCatalogBody:
     type: object