diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
index 059a8fdfd3..b9eb51842e 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
@@ -113,7 +113,7 @@ limitations under the License.
       }
       .subHeader {
         flex-wrap: wrap;
-        margin: 0 var(--default-horizontal-margin) .75em;
+        padding: 0 var(--default-horizontal-margin) .75em;
       }
       .subHeader > div {
         margin-top: .25em;
diff --git a/polygerrit-ui/app/elements/shared/gr-fixed-panel/gr-fixed-panel.html b/polygerrit-ui/app/elements/shared/gr-fixed-panel/gr-fixed-panel.html
index 47acd0cc94..226092fca4 100644
--- a/polygerrit-ui/app/elements/shared/gr-fixed-panel/gr-fixed-panel.html
+++ b/polygerrit-ui/app/elements/shared/gr-fixed-panel/gr-fixed-panel.html
@@ -22,6 +22,7 @@ limitations under the License.
   <template>
     <style include="shared-styles">
       :host {
+        box-sizing: border-box;
         display: block;
         min-height: var(--header-height);
         position: relative;