diff --git a/src/util/goop.ts b/src/util/goop.ts
index 9a219fd..ac9f34e 100644
--- a/src/util/goop.ts
+++ b/src/util/goop.ts
@@ -4,24 +4,29 @@
  * This is just cause I gotta stick to not touching Public templates
  */
 
+// keys whose Go field name can't be derived from separators alone
+type Special = { id: "ID"; flatrate: "FlatRate" };
+
 type Camel<S extends string> =
   S extends "id" ? "ID" :
   S extends `${infer H}.${infer T}` ? `${H}${Capitalize<Camel<T>>}` :
   S extends `${infer H}_${infer T}` ? `${H}${Capitalize<Camel<T>>}` : S;
 
-type Pascal<S extends string> = S extends "id" ? "ID" : Capitalize<Camel<S>>;
+type Pascal<S extends string> =
+  S extends keyof Special ? Special[S] : Capitalize<Camel<S>>;
 
 export type Camelize<T> =
   T extends readonly (infer U)[] ? Camelize<U>[] :
   T extends object ? { [K in keyof T as Pascal<K & string>]: Camelize<T[K]> } :
   T;
 
+const special: Record<string, string> = { id: "ID", flatrate: "FlatRate" };
+
 const pascalKey = (k: string) =>
-  k === "id"
-    ? "ID"
-    : k
-        .replace(/[._](\w)/g, (_, c) => c.toUpperCase())
-        .replace(/^\w/, (c) => c.toUpperCase());
+  special[k] ??
+  k
+    .replace(/[._](\w)/g, (_, c) => c.toUpperCase())
+    .replace(/^\w/, (c) => c.toUpperCase());
 
 export default function ungoop<T>(obj: T): Camelize<T> {
   return (