diff --git a/bot.go b/bot.go
index 16bfecc..8979bac 100644
--- a/bot.go
+++ b/bot.go
@@ -418,7 +418,9 @@ func fetchLCPModelsWithStatus() (*models.LCPModels, error) {
 	if err := json.NewDecoder(resp.Body).Decode(data); err != nil {
 		return nil, err
 	}
+	localModelsMu.Lock()
 	localModelsData = data
+	localModelsMu.Unlock()
 	return data, nil
 }
 
diff --git a/extra/kokoro_onnx.go b/extra/kokoro_onnx.go
index fe5abfb..add401d 100644
--- a/extra/kokoro_onnx.go
+++ b/extra/kokoro_onnx.go
@@ -99,6 +99,11 @@ func (o *KokoroONNXOrator) ensureInitialized(modelPath string) error {
 			} else {
 				// Shape is (510, 1, 256), we want the last 256 values (or first? let's use mean or just pick one)
 				// Actually, let's average across all 510 to get a single 256-dim vector
+				if len(styleVec) != 510*256 {
+					o.logger.Error("voice embedding has unexpected size", "len", len(styleVec))
+					err = fmt.Errorf("voice embedding has unexpected size", "len", len(styleVec))
+					return err
+				}
 				o.styleVector = make([]float32, 256)
 				for i := 0; i < 256; i++ {
 					var sum float32