diff --git a/packages/cosmic-proto/src/helpers.ts b/packages/cosmic-proto/src/helpers.ts
index 237d985d316..feea08b879a 100644
--- a/packages/cosmic-proto/src/helpers.ts
+++ b/packages/cosmic-proto/src/helpers.ts
@@ -1,6 +1,7 @@
 import type { QueryAllBalancesRequest } from './codegen/cosmos/bank/v1beta1/query.js';
 import type { MsgSend } from './codegen/cosmos/bank/v1beta1/tx.js';
 import type { MsgDelegate } from './codegen/cosmos/staking/v1beta1/tx.js';
+import type { RequestQuery } from './codegen/tendermint/abci/types.js';
 
 /**
  * The result of Any.toJSON(). The type in cosms-types says it returns
@@ -49,3 +50,24 @@ export const typedJson = <T extends keyof Proto3Shape>(
 export type Base64Any<T> = {
   [Prop in keyof T]: T[Prop] extends Uint8Array ? string : T[Prop];
 };
+
+// TODO make codegen toJSON() return these instead of unknown
+// https://github.com/cosmology-tech/telescope/issues/605
+/**
+ * Mimics behavor of .toJSON(), converting Uint8Array to base64 strings
+ * and bigints to strings
+ */
+export type JsonSafe<T> = {
+  [Prop in keyof T]: T[Prop] extends Uint8Array
+    ? string
+    : T[Prop] extends bigint
+      ? string
+      : T[Prop];
+};
+
+/**
+ * The result of RequestQuery.toJSON(). The type in cosms-types says it returns
+ * `unknown` but it's actually this. The Uint8Array fields are base64 encoded, while
+ * bigint fields are strings.
+ */
+export type RequestQueryJson = JsonSafe<RequestQuery>;