diff --git a/pdf/pdf.d.ts b/pdf/pdf.d.ts
index a9d04c4c0b..cf74bb658c 100644
--- a/pdf/pdf.d.ts
+++ b/pdf/pdf.d.ts
@@ -195,6 +195,7 @@ interface PDFRenderImageLayer {
 
 interface PDFRenderParams {
 	canvasContext: CanvasRenderingContext2D;
+	viewport?: PDFPageViewport;
 	textLayer?: PDFRenderTextLayer;
 	imageLayer?: PDFRenderImageLayer;
 	continueCallback?: (_continue: () => void) => void;