diff --git a/packages/main/src/themes/Dialog.css b/packages/main/src/themes/Dialog.css
index 528b46be043f..668b7deec9f8 100644
--- a/packages/main/src/themes/Dialog.css
+++ b/packages/main/src/themes/Dialog.css
@@ -17,6 +17,7 @@
 	height: 100%;
 	max-height: 100%;
 	max-width: 100%;
+	border-radius: 0;
 }
 
 .ui5-popup-header-root {