diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
index ccbf5a99d5..c1f9e2b728 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.html
@@ -177,7 +177,7 @@ limitations under the License.
         }
         gr-reply-dialog {
           min-width: initial;
-          width: 90vw;
+          width: 100vw;
         }
         .downloadContainer {
           display: none;
@@ -213,6 +213,9 @@ limitations under the License.
           flex: initial;
           margin-right: 0;
         }
+        .scrollable {
+          @apply(--layout-scroll);
+        }
       }
     </style>
     <div class="container loading" hidden$="[[!_loading]]">Loading...</div>
@@ -348,6 +351,7 @@ limitations under the License.
           on-close="_handleDownloadDialogClose"></gr-download-dialog>
     </gr-overlay>
     <gr-overlay id="replyOverlay"
+        class="scrollable"
         no-cancel-on-outside-click
         on-iron-overlay-opened="_handleReplyOverlayOpen"
         with-backdrop>
diff --git a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.html b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.html
index 761f0a5b00..7c62e8a37c 100644
--- a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.html
+++ b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.html
@@ -138,6 +138,14 @@ limitations under the License.
       .action:visited {
         color: #00e;
       }
+      @media screen and (max-width: 50em) {
+        :host {
+          max-height: none;
+        }
+        .container {
+          max-height: none;
+        }
+      }
     </style>
     <div class="container">
       <section class="peopleContainer">