diff --git a/packages/style-utilities/src/utilities/icons.ts b/packages/style-utilities/src/utilities/icons.ts
index 38976f7c6aefe3..9c454f89215a39 100644
--- a/packages/style-utilities/src/utilities/icons.ts
+++ b/packages/style-utilities/src/utilities/icons.ts
@@ -219,7 +219,7 @@ export function setIconOptions(options: Partial<IIconOptions>): void {
 }
 
 let _missingIcons: string[] = [];
-let _missingIconsTimer: number | undefined = undefined;
+let _missingIconsTimer: ReturnType<typeof setTimeout> | undefined = undefined;
 
 function _warnDuplicateIcon(iconName: string): void {
   const options = _iconSettings.__options;
@@ -229,7 +229,7 @@ function _warnDuplicateIcon(iconName: string): void {
   if (!options.disableWarnings) {
     _missingIcons.push(iconName);
     if (_missingIconsTimer === undefined) {
-      _missingIconsTimer = window.setTimeout(() => {
+      _missingIconsTimer = setTimeout(() => {
         warn(
           `Some icons were re-registered. Applications should only call registerIcons for any given ` +
             `icon once. Redefining what an icon is may have unintended consequences. Duplicates ` +