diff --git a/speech-to-text/v1.ts b/speech-to-text/v1.ts
index c02662aff5..380726a585 100644
--- a/speech-to-text/v1.ts
+++ b/speech-to-text/v1.ts
@@ -275,6 +275,7 @@ namespace SpeechToTextV1 {
     timestamps?: boolean;
     profanityFilter?: boolean;
     smartFormatting?: boolean;
+    smartFormattingVersion?: number;
     speakerLabels?: boolean;
     grammarName?: string;
     redaction?: boolean;