diff --git a/packages/dmn-js-boxed-expression/assets/css/dmn-js-boxed-expression.css b/packages/dmn-js-boxed-expression/assets/css/dmn-js-boxed-expression.css
index 9bbcf478b..0adb191f8 100644
--- a/packages/dmn-js-boxed-expression/assets/css/dmn-js-boxed-expression.css
+++ b/packages/dmn-js-boxed-expression/assets/css/dmn-js-boxed-expression.css
@@ -104,6 +104,7 @@
 }
 
 .dmn-boxed-expression-container .textarea.editor {
+  height: 100%;
   cursor: text;
 }