diff --git a/src/components/SideTray/SideTray.tsx b/src/components/SideTray/SideTray.tsx
index 462f1322..05ff5527 100644
--- a/src/components/SideTray/SideTray.tsx
+++ b/src/components/SideTray/SideTray.tsx
@@ -1,5 +1,6 @@
 import React, { useEffect, ReactNode, CSSProperties } from 'react';
 import PropTypes from 'prop-types';
+import classNames from 'classnames';
 
 // Rover UI dependencies
 import { parseCssSize } from '../../shared/css-utils';
@@ -13,7 +14,7 @@ interface SideTrayProps {
   direction?: string;
   height?: string | number;
   onClose: (...args) => void;
-  style?: object;
+  style?: CSSProperties;
   visible?: boolean;
   width?: string | number;
 }
@@ -123,7 +124,7 @@ const SideTray: SideTrayType = ({
           ...(!visible ? { transform: hideTransformStyle } : {}),
           ...style,
         }}
-        className={`${styles.SideTray} ${className}`}
+        className={classNames(styles.SideTray, className)}
       >
         <div className={styles.container}>{children}</div>
       </div>