diff --git a/components/ui/sheet.tsx b/components/ui/sheet.tsx
index 7bf2857..913776e 100644
--- a/components/ui/sheet.tsx
+++ b/components/ui/sheet.tsx
@@ -25,6 +25,15 @@ function SheetClose({
 function SheetPortal({
   ...props
 }: React.ComponentProps<typeof SheetPrimitive.Portal>) {
+  // Radix's Portal calls createPortal(children, document.body) as soon as it
+  // renders. During static prerendering there's no `document`, so gate the
+  // portal behind an effect that only runs in the browser. Closed sheets
+  // render nothing on the server anyway, so there's no visual/hydration change.
+  const [mounted, setMounted] = React.useState(false)
+  React.useEffect(() => setMounted(true), [])
+
+  if (!mounted) return null
+
   return <SheetPrimitive.Portal data-slot="sheet-portal" {...props} />
 }