diff --git a/apps/client/src/widgets/tab_row.ts b/apps/client/src/widgets/tab_row.ts
index 52eb585fc..83999d876 100644
--- a/apps/client/src/widgets/tab_row.ts
+++ b/apps/client/src/widgets/tab_row.ts
@@ -473,7 +473,7 @@ export default class TabRowWidget extends BasicWidget {
         const totalTabsWidthUsingTarget = flooredClampedTargetWidth * numberOfTabs + marginWidth;
         const totalExtraWidthDueToFlooring = tabsContainerWidth - totalTabsWidthUsingTarget;
 
-        const widths = [];
+        const widths: number[] = [];
         let extraWidthRemaining = totalExtraWidthDueToFlooring;
 
         for (let i = 0; i < numberOfTabs; i += 1) {