diff --git a/common/static/js/vendor/tinymce/js/tinymce/plugins/codemirror/source.html b/common/static/js/vendor/tinymce/js/tinymce/plugins/codemirror/source.html
index 8d827d8412..11e11be5e0 100644
--- a/common/static/js/vendor/tinymce/js/tinymce/plugins/codemirror/source.html
+++ b/common/static/js/vendor/tinymce/js/tinymce/plugins/codemirror/source.html
@@ -232,7 +232,7 @@ function submit() {
 
     .CodeMirror {
         height: 100%;
-        font-size: 12px;
+        font-size: 13px;
         line-height: 18px;
     }