diff --git a/src/js/slide/slide.js b/src/js/slide/slide.js
index <HASH>..<HASH> 100644
--- a/src/js/slide/slide.js
+++ b/src/js/slide/slide.js
@@ -592,6 +592,10 @@ class Slide {
       );
 
       this.zoomLevels.update(this.width, this.height, this.panAreaSize);
+
+      pswp.dispatch('calcSlideSize', {
+        slide: this
+      });
     } else {
       this.width = 0;
       this.height = 0;
added calcSlideSize event (when size of slide is calculated, but before it's applied)