diff --git a/.changeset/fix-rpccompatible-symbol-keys.md b/.changeset/fix-rpccompatible-symbol-keys.md
new file mode 100644
index 0000000..0b9bbf8
--- /dev/null
+++ b/.changeset/fix-rpccompatible-symbol-keys.md
@@ -0,0 +1,5 @@
+---
+"capnweb": patch
+---
+
+Fix RpcCompatible type to filter out symbol keys instead of mapping them to never
diff --git a/src/types.d.ts b/src/types.d.ts
index c5a2897..2d00d96 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -8,8 +8,8 @@
 // TypeScript uses *structural* typing meaning anything with the same shape as type `T` is a `T`.
 // For the classes exported by `cloudflare:workers` we want *nominal* typing (i.e. we only want to
 // accept `WorkerEntrypoint` from `cloudflare:workers`, not any other class with the same shape)
-export const __RPC_STUB_BRAND: '__RPC_STUB_BRAND';
-export const __RPC_TARGET_BRAND: '__RPC_TARGET_BRAND';
+export const __RPC_STUB_BRAND: "__RPC_STUB_BRAND";
+export const __RPC_TARGET_BRAND: "__RPC_TARGET_BRAND";
 export interface RpcTargetBranded {
   [__RPC_TARGET_BRAND]: never;
 }
@@ -33,7 +33,9 @@ export type RpcCompatible<T> =
   | Array<T extends Array<infer U> ? RpcCompatible<U> : never>
   | ReadonlyArray<T extends ReadonlyArray<infer U> ? RpcCompatible<U> : never>
   | {
-      [K in keyof T]: K extends number | string ? RpcCompatible<T[K]> : never;
+      [K in keyof T as K extends string | number ? K : never]: RpcCompatible<
+        T[K]
+      >;
     }
   | Promise<T extends Promise<infer U> ? RpcCompatible<U> : never>
   // Special types
@@ -48,8 +50,9 @@ interface StubBase<T extends RpcCompatible<T>> extends Disposable {
   dup(): this;
   onRpcBroken(callback: (error: any) => void): void;
 }
-export type Stub<T extends RpcCompatible<T>> =
-    T extends object ? Provider<T> & StubBase<T> : StubBase<T>;
+export type Stub<T extends RpcCompatible<T>> = T extends object
+  ? Provider<T> & StubBase<T>
+  : StubBase<T>;
 
 type TypedArray =
   | Uint8Array
@@ -123,7 +126,7 @@ type UnstubifyInner<T> =
 
 // You can put promises anywhere in the params and they'll be resolved before delivery.
 // (This also covers RpcPromise, because it's defined as being a Promise.)
-type Unstubify<T> = UnstubifyInner<T> | Promise<UnstubifyInner<T>>
+type Unstubify<T> = UnstubifyInner<T> | Promise<UnstubifyInner<T>>;
 
 type UnstubifyAll<A extends any[]> = { [I in keyof A]: Unstubify<A[I]> };