diff --git a/src/components/views/elements/ImageView.tsx b/src/components/views/elements/ImageView.tsx
index 2628170f9c..985160019e 100644
--- a/src/components/views/elements/ImageView.tsx
+++ b/src/components/views/elements/ImageView.tsx
@@ -43,14 +43,14 @@ const ZOOM_COEFFICIENT = 0.0025;
 // If we have moved only this much we can zoom
 const ZOOM_DISTANCE = 10;
 
-interface IProps {
+export interface IProps {
     src: string; // the source of the image being displayed
     name?: string; // the main title ('name') for the image
     link?: string; // the link (if any) applied to the name of the image
     width?: number; // width of the image src in pixels
     height?: number; // height of the image src in pixels
     fileSize?: number; // size of the image src in bytes
-    onFinished(): void; // callback when the lightbox is dismissed
+    onFinished?(): void; // callback when the lightbox is dismissed
 
     // the event (if any) that the Image is displaying. Used for event-specific stuff like
     // redactions, senders, timestamps etc.  Other descriptors are taken from the explicit