diff --git a/dev/misc/png.html b/dev/misc/png.html
index d5a90fd99..dd1d629ec 100644
--- a/dev/misc/png.html
+++ b/dev/misc/png.html
@@ -94,7 +94,7 @@
             console.log(`${ browser.guid } is good to go`)
 
             document.querySelector('#igv-save-as-png-button').addEventListener('click', () => {
-                browser.savePNGtoFile('saveIGVJSToPNG.png')
+                browser.savePNGtoFile(`igvjs-screendump-${ browser.guid }.png`)
             })
 
         })
diff --git a/js/browser.js b/js/browser.js
index f9c61419e..b51204d09 100755
--- a/js/browser.js
+++ b/js/browser.js
@@ -419,13 +419,11 @@ class Browser {
     }
 
     savePNGtoFile(filename) {
-
-        html2canvas(document.querySelector('.igv-column-container'), { allowTaint: true }).then(canvas => {
+        html2canvas(this.columnContainer, { allowTaint: true }).then(canvas => {
             const path = filename || 'igvjs.png'
             const data = canvas.toDataURL('image/png')
             FileUtils.download(path, data)
         })
-
     }
 
     /**