diff --git a/src/calibre/gui2/tag_browser/view.py b/src/calibre/gui2/tag_browser/view.py
index 57d7e54c56..4535241f77 100644
--- a/src/calibre/gui2/tag_browser/view.py
+++ b/src/calibre/gui2/tag_browser/view.py
@@ -117,6 +117,7 @@ class TagsView(QTreeView): # {{{
                 QTreeView::item:hover {
                     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 #e7effd, stop: 1 #cbdaf1);
                     border: 1px solid #bfcde4;
+                    border-radius: 8px;
                 }
         ''')
 
diff --git a/src/calibre/gui2/viewer/toc.py b/src/calibre/gui2/viewer/toc.py
index bcaa4f289f..cb105630e6 100644
--- a/src/calibre/gui2/viewer/toc.py
+++ b/src/calibre/gui2/viewer/toc.py
@@ -32,6 +32,7 @@ class TOCView(QTreeView):
                 QTreeView::item:hover {
                     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1, stop: 0 #e7effd, stop: 1 #cbdaf1);
                     border: 1px solid #bfcde4;
+                    border-radius: 8px;
                 }
                 QHeaderView::section {
                     background-color: qlineargradient(x1:0, y1:0, x2:0, y2:1,