diff --git a/.changeset/silver-parents-breathe.md b/.changeset/silver-parents-breathe.md
new file mode 100644
index 0000000000..b25bf595f5
--- /dev/null
+++ b/.changeset/silver-parents-breathe.md
@@ -0,0 +1,5 @@
+---
+"uploadthing": patch
+---
+
+fix(h3): always return a response to support non-preemptive routers
diff --git a/packages/uploadthing/src/h3.ts b/packages/uploadthing/src/h3.ts
index 2612043a7c..0f0576186c 100644
--- a/packages/uploadthing/src/h3.ts
+++ b/packages/uploadthing/src/h3.ts
@@ -71,7 +71,7 @@ export const createRouteHandler = <TRouter extends FileRouter>(
       return "An unknown error occurred";
     }
 
-    return response.body;
+    return response.body ?? "OK";
   });
 };