diff --git a/packages/opencode/src/cli/cmd/tui/session.tsx b/packages/opencode/src/cli/cmd/tui/session.tsx
index 831d092cd..46bb41d2a 100644
--- a/packages/opencode/src/cli/cmd/tui/session.tsx
+++ b/packages/opencode/src/cli/cmd/tui/session.tsx
@@ -123,6 +123,7 @@ function UserMessage(props: { message: UserMessage; parts: Part[] }) {
       backgroundColor={Theme.backgroundPanel}
       customBorderChars={SplitBorder.customBorderChars}
       borderColor={Theme.secondary}
+      flexShrink={0}
     >
       <text>{text()?.text}</text>
       <text>