diff --git a/packages/tui/src/routes/session/index.tsx b/packages/tui/src/routes/session/index.tsx
index 9d35bb65331..0e142cceb8f 100644
--- a/packages/tui/src/routes/session/index.tsx
+++ b/packages/tui/src/routes/session/index.tsx
@@ -2787,6 +2787,7 @@ function BlockToolContent(props: BlockToolProps & { borderColor: RGBA }) {
   return (
     <box
       border={["left"]}
+      flexShrink={0}
       paddingTop={1}
       paddingBottom={1}
       paddingLeft={2}