diff --git a/ts/components/ConversationList.tsx b/ts/components/ConversationList.tsx
index b23b4dbd871f..2a2c1a0440e5 100644
--- a/ts/components/ConversationList.tsx
+++ b/ts/components/ConversationList.tsx
@@ -340,7 +340,11 @@ export const ConversationList: React.FC<PropsType> = ({
       rowHeight={calculateRowHeight}
       rowRenderer={renderRow}
       scrollToIndex={scrollToRowIndex}
-      style={{ overflow: scrollable ? 'overlay' : 'hidden' }}
+      style={{
+        // See `<Timeline>` for an explanation of this `any` cast.
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        overflowY: scrollable ? ('overlay' as any) : 'hidden',
+      }}
       tabIndex={-1}
       width={width}
     />
diff --git a/ts/components/conversation/Timeline.tsx b/ts/components/conversation/Timeline.tsx
index a79a87e890ae..3f650c5aeb14 100644
--- a/ts/components/conversation/Timeline.tsx
+++ b/ts/components/conversation/Timeline.tsx
@@ -1365,7 +1365,16 @@ export class Timeline extends React.PureComponent<PropsType, StateType> {
               scrollToIndex={scrollToIndex}
               tabIndex={-1}
               width={width}
-              style={{ overflow: 'overlay' }}
+              style={{
+                // `overlay` is [a nonstandard value][0] so it's not supported. See [this
+                //   issue][1].
+                //
+                // [0]: https://developer.mozilla.org/en-US/docs/Web/CSS/overflow#values
+                // [1]: https://github.com/frenic/csstype/issues/62#issuecomment-937238313
+                //
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                overflowY: 'overlay' as any,
+              }}
             />
           );
         }}