diff --git a/src/components/MDXRenderer.tsx b/src/components/MDXRenderer.tsx
index 2ee97f1..f15d90b 100644
--- a/src/components/MDXRenderer.tsx
+++ b/src/components/MDXRenderer.tsx
@@ -1,3 +1,7 @@
+// compileMDXComponent evaluates code with `new Function`. The CSP has no
+// 'unsafe-eval', which is safe only while this runs on the server, so make
+// importing it from a Client Component a build error.
+import "server-only";
 import * as runtime from "react/jsx-runtime";
 
 interface MDXRendererProps {