diff --git a/addons/web_editor/static/src/js/backend/convert_inline.js b/addons/web_editor/static/src/js/backend/convert_inline.js
index 1025f1fd74b..31639e681e8 100644
--- a/addons/web_editor/static/src/js/backend/convert_inline.js
+++ b/addons/web_editor/static/src/js/backend/convert_inline.js
@@ -1187,7 +1187,7 @@ function _getMatchedCSSRules(node, cssRules) {
     }
 
     for (const [key, value] of Object.entries(processedStyle)) {
-        if (value.endsWith('important')) {
+        if (value && value.endsWith('important')) {
             processedStyle[key] = value.replace(/\s*!important\s*$/, '');
         }
     };