diff --git a/internal/errors/lb.go b/internal/errors/lb.go
index 5215f366c6..c7eceeb5dd 100644
--- a/internal/errors/lb.go
+++ b/internal/errors/lb.go
@@ -25,4 +25,9 @@ var (
 
 	// ErrIndexNotFound represents an error that the index not found.
 	ErrIndexNotFound = New("index not found")
+
+	// ErrInvalidSearchConfig represents an error that the invalid Search Configuration.
+	ErrInvalidSearchConfig = func(msg string) error {
+		return Errorf("Invalid Search_Config: %s", msg)
+	}
 )
diff --git a/pkg/gateway/lb/handler/grpc/aggregation.go b/pkg/gateway/lb/handler/grpc/aggregation.go
index 24ad0925cd..674af408d0 100644
--- a/pkg/gateway/lb/handler/grpc/aggregation.go
+++ b/pkg/gateway/lb/handler/grpc/aggregation.go
@@ -65,6 +65,10 @@ func (s *server) aggregationSearch(
 		}
 	}()
 
+	if bcfg == nil {
+		return nil, nil, errors.ErrInvalidSearchConfig("bcfg is nil in aggregationSearch")
+	}
+
 	num := aggr.GetNum()
 	min := int(bcfg.GetMinNum())
 
diff --git a/pkg/gateway/lb/handler/grpc/handler.go b/pkg/gateway/lb/handler/grpc/handler.go
index ca21f84083..ee7ec9ce16 100644
--- a/pkg/gateway/lb/handler/grpc/handler.go
+++ b/pkg/gateway/lb/handler/grpc/handler.go
@@ -438,6 +438,28 @@ func (s *server) doSearch(
 		}
 	}()
 
+	if cfg == nil {
+		err = errors.ErrInvalidSearchConfig("search config is nil in doSearch")
+		err = status.WrapWithInvalidArgument(apiName+"/doSearch", err, &errdetails.RequestInfo{
+			RequestId:   "Search_Config is nil",
+			ServingData: "Search_Config is nil",
+		},
+			&errdetails.BadRequest{
+				FieldViolations: []*errdetails.BadRequestFieldViolation{
+					{
+						Field:       "Search_Config is nil",
+						Description: err.Error(),
+					},
+				},
+			})
+		if span != nil {
+			span.RecordError(err)
+			span.SetAttributes(trace.StatusCodeInvalidArgument(err.Error())...)
+			span.SetStatus(trace.StatusError, err.Error())
+		}
+		return nil, nil, err
+	}
+
 	var (
 		num     = int(cfg.GetNum())
 		fnum    int
diff --git a/pkg/tools/cli/loadtest/service/search.go b/pkg/tools/cli/loadtest/service/search.go
index e01be7c943..3f7d34e4fe 100644
--- a/pkg/tools/cli/loadtest/service/search.go
+++ b/pkg/tools/cli/loadtest/service/search.go
@@ -34,6 +34,11 @@ func searchRequestProvider(dataset assets.Dataset) (func() any, int, error) {
 			}
 			ret = &payload.Search_Request{
 				Vector: v.([]float32),
+				Config: &payload.Search_Config{
+					Num:     10,
+					Radius:  -1,
+					Epsilon: 0.1,
+				},
 			}
 		}
 		return ret