diff --git a/packages/demo-protobuf/src/decorator.spec.ts b/packages/demo-protobuf/src/decorator.spec.ts
index eb934b65..776f7f4f 100644
--- a/packages/demo-protobuf/src/decorator.spec.ts
+++ b/packages/demo-protobuf/src/decorator.spec.ts
@@ -1,19 +1,30 @@
 /* eslint-disable @typescript-eslint/camelcase */
 import { assert } from "@cosmjs/utils";
+import { Message } from "protobufjs";
 
-import { myRegistry } from "./decorator";
+import { CosmosField, CosmosMessage } from "./decorator";
+import { Registry } from "./registry";
 
 describe("decorator demo", () => {
   it("works with a custom msg", () => {
     const typeUrl = "/demo.MsgDemo";
-    const MsgDemo = myRegistry.lookupType(typeUrl)!;
+    const myRegistry = new Registry();
+
+    @CosmosMessage(myRegistry, typeUrl)
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    class MsgDemo extends Message<{}> {
+      @CosmosField.String(1)
+      public readonly example: string = "";
+    }
+
+    const MsgDemoT = myRegistry.lookupType(typeUrl)!;
     const TxBody = myRegistry.lookupType("/cosmos.tx.TxBody")!;
     const Any = myRegistry.lookupType("/google.protobuf.Any")!;
 
-    const msgDemo = MsgDemo.create({
+    const msgDemo = MsgDemoT.create({
       example: "Some example text",
     });
-    const msgDemoBytes = MsgDemo.encode(msgDemo).finish();
+    const msgDemoBytes = MsgDemoT.encode(msgDemo).finish();
     const msgDemoWrapped = Any.create({
       type_url: typeUrl,
       value: msgDemoBytes,
@@ -31,8 +42,7 @@ describe("decorator demo", () => {
     assert(msg.type_url);
     assert(msg.value);
 
-    const decoder = myRegistry.lookupType(msg.type_url)!;
-    const msgDemoDecoded = decoder.decode(msg.value);
+    const msgDemoDecoded = MsgDemoT.decode(msg.value);
     expect(msgDemoDecoded.example).toEqual(msgDemo.example);
   });
 });
diff --git a/packages/demo-protobuf/src/decorator.ts b/packages/demo-protobuf/src/decorator.ts
index 8cc918d7..febf37c4 100644
--- a/packages/demo-protobuf/src/decorator.ts
+++ b/packages/demo-protobuf/src/decorator.ts
@@ -2,14 +2,12 @@ import { Constructor, Field, Message, TypeDecorator, util } from "protobufjs";
 
 import { Registry } from "./registry";
 
-export const myRegistry = new Registry();
-
 function getTypeName(typeUrl: string): string {
   const parts = typeUrl.split(".");
   return parts[parts.length - 1];
 }
 
-function CosmosMessage(registry: Registry, typeUrl: string): TypeDecorator<any> {
+export function CosmosMessage(registry: Registry, typeUrl: string): TypeDecorator<any> {
   return (constructor: Constructor<Message<any>>) => {
     const typeName = getTypeName(typeUrl);
     const generatedType = util.decorateType(constructor, typeName);
@@ -17,12 +15,6 @@ function CosmosMessage(registry: Registry, typeUrl: string): TypeDecorator<any>
   };
 }
 
-const CosmosField = {
+export const CosmosField = {
   String: (id: number) => Field.d(id, "string"),
 };
-
-@CosmosMessage(myRegistry, "/demo.MsgDemo")
-export class MsgDemo extends Message<{}> {
-  @CosmosField.String(1)
-  public readonly example: string = "";
-}
diff --git a/packages/demo-protobuf/types/decorator.d.ts b/packages/demo-protobuf/types/decorator.d.ts
index 0053b88a..ef014457 100644
--- a/packages/demo-protobuf/types/decorator.d.ts
+++ b/packages/demo-protobuf/types/decorator.d.ts
@@ -1,6 +1,6 @@
-import { Message } from "protobufjs";
+import { TypeDecorator } from "protobufjs";
 import { Registry } from "./registry";
-export declare const myRegistry: Registry;
-export declare class MsgDemo extends Message<{}> {
-  readonly example: string;
-}
+export declare function CosmosMessage(registry: Registry, typeUrl: string): TypeDecorator<any>;
+export declare const CosmosField: {
+  String: (id: number) => import("protobufjs").FieldDecorator;
+};