fixed compile errors

1 files changed, 1 insertions, 1 deletions

diff --git a/src/client/views/pdf/PDFViewer.tsx b/src/client/views/pdf/PDFViewer.tsx
index a9053fd55..a7c1990e9 100644
--- a/src/client/views/pdf/PDFViewer.tsx
+++ b/src/client/views/pdf/PDFViewer.tsx
@@ -621,7 +621,7 @@ export class PDFViewer extends DocAnnotatableComponent<IViewerProps, PdfDocument
 
     @computed get annotationLayer() {
         TraceMobx();
-        return <div className="pdfViewer-annotationLayer" style={{ height: (this.Document.nativeHeight || 0), transform: `scale(${this._zoomed})` }} ref={this._annotationLayer}>
+        return <div className="pdfViewer-annotationLayer" style={{ height: NumCast(this.Document.nativeHeight), transform: `scale(${this._zoomed})` }} ref={this._annotationLayer}>
             {this.nonDocAnnotations.sort((a, b) => NumCast(a.y) - NumCast(b.y)).map((anno, index) =>
                 <Annotation {...this.props} focus={this.props.focus} dataDoc={this.dataDoc!} fieldKey={this.props.fieldKey} anno={anno} key={`${anno[Id]}-annotation`} />)}
         </div>;