diff --git a/.changeset/seven-oranges-punch.md b/.changeset/seven-oranges-punch.md
new file mode 100644
index 00000000..2b6e2474
--- /dev/null
+++ b/.changeset/seven-oranges-punch.md
@@ -0,0 +1,7 @@
+---
+"@cambly/syntax-core": minor
+"@cambly/syntax-floating-components": minor
+"@cambly/syntax-utils": minor
+---
+
+Add 'use client' to every Syntax exported JS file
diff --git a/tsup.config.ts b/tsup.config.ts
index 87037ce8..1e1596ee 100644
--- a/tsup.config.ts
+++ b/tsup.config.ts
@@ -26,6 +26,9 @@ export default defineConfig({
   skipNodeModulesBundle: true,
   esbuildOptions(options) {
     options.chunkNames = "__chunks/[hash]";
+    options.banner = {
+      js: '"use client"',
+    };
   },
   // ESBuild does not yet support CSS Modules
   // https://github.com/egoist/tsup/issues/536#issuecomment-1302012400