diff --git a/app/assets/stylesheets/pages/boards.scss b/app/assets/stylesheets/pages/boards.scss
index df858cffe09..6039cda96d8 100644
--- a/app/assets/stylesheets/pages/boards.scss
+++ b/app/assets/stylesheets/pages/boards.scss
@@ -431,7 +431,10 @@
   margin: 5px;
 }
 
-.page-with-layout-nav.page-with-sub-nav .issue-boards-sidebar {
+.page-with-layout-nav.page-with-sub-nav .issue-boards-sidebar,
+.page-with-new-sidebar.page-with-sidebar .issue-boards-sidebar {
+  position: absolute;
+
   &.right-sidebar {
     top: 0;
     bottom: 0;
diff --git a/changelogs/unreleased/issue-boards-close-icon-size.yml b/changelogs/unreleased/issue-boards-close-icon-size.yml
new file mode 100644
index 00000000000..bc6bda0e50d
--- /dev/null
+++ b/changelogs/unreleased/issue-boards-close-icon-size.yml
@@ -0,0 +1,4 @@
+---
+title: Fixed issue boards sidebar close icon size
+merge_request:
+author: