diff --git a/public/app.mjs b/public/app.mjs
index 165001a..7d3b891 100644
--- a/public/app.mjs
+++ b/public/app.mjs
@@ -2107,6 +2107,10 @@ function open_bin_editor(bin) {
 	bin_editor_bin_id = bin.id;
 	document.getElementById('bin-editor-name').value = bin.name;
 
+	// Show dialog first so the canvas has correct layout dimensions before
+	// load_image reads parentElement.clientWidth to size itself.
+	dlg.showModal();
+
 	const canvas = document.getElementById('bin-editor-canvas');
 	bin_editor_instance = new Grid_Setup(canvas);
 	bin_editor_instance.set_rows(1);
@@ -2116,8 +2120,6 @@ function open_bin_editor(bin) {
 			bin_editor_instance.set_corners(bin.corners);
 		}
 	});
-
-	dlg.showModal();
 }
 
 // ---------------------------------------------------------------------------