diff --git a/frontend/src/components/seafile-codemirror/style.css b/frontend/src/components/seafile-codemirror/style.css
index 7d94512115..18dd9517f0 100644
--- a/frontend/src/components/seafile-codemirror/style.css
+++ b/frontend/src/components/seafile-codemirror/style.css
@@ -11,6 +11,10 @@
   max-width: 950px;
 }
 
+.text-file-view .cm-editor.cm-focused {
+  outline: none;
+}
+
 .text-file-view .cm-scroll {
   min-height: 300px;
 }