diff --git a/packages/protobuf/src/index.ts b/packages/protobuf/src/index.ts
index 5825d4ed67c..84458a6c2da 100644
--- a/packages/protobuf/src/index.ts
+++ b/packages/protobuf/src/index.ts
@@ -3,6 +3,7 @@ export * from './encode';
 export * as Messages from './messages';
 export * from './types';
 export { parseConfigure, createMessageFromName, createMessageFromType } from './utils';
+export { loadDefinitions } from './load-definitions';
 export * as MessagesSchema from './messages-schema';
 // It's problem to reexport enums when they are under MessagesSchema namespace, check packages/connect/src/types/device.ts
 export { DeviceModelInternal } from './messages-schema';
diff --git a/packages/protobuf/src/load-definitions.ts b/packages/protobuf/src/load-definitions.ts
new file mode 100644
index 00000000000..86c48a73dd9
--- /dev/null
+++ b/packages/protobuf/src/load-definitions.ts
@@ -0,0 +1,49 @@
+import { Root } from 'protobufjs/light';
+
+type Definitions = Record<string, unknown>;
+
+export const loadDefinitions = async (
+    messages: Root,
+    packageName: string,
+    packageLoader: () => Definitions | Promise<Definitions>,
+) => {
+    // check if package already exists
+    try {
+        const pkg = messages.lookup(packageName);
+        if (pkg) {
+            return;
+        }
+    } catch {}
+
+    // get current MessageType enum
+    let enumType;
+    try {
+        enumType = messages.lookupEnum('MessageType');
+    } catch {}
+
+    // load definitions
+    const packageMessages = await packageLoader();
+    const pkg = messages.define(packageName, packageMessages);
+    // get package MessageType enum
+    let packageEnumType;
+    try {
+        packageEnumType = pkg.lookupEnum('MessageType');
+    } catch {}
+
+    // merge MessageType enums
+    if (enumType && packageEnumType) {
+        try {
+            // move values from nested enum to top level
+            Object.keys(packageEnumType.values).forEach(key => {
+                enumType.add(key, packageEnumType.values[key]);
+            });
+            // remove nested enum
+            pkg.remove(packageEnumType);
+        } catch (e) {
+            // remove whole package on merge error
+            messages.remove(pkg);
+
+            throw e;
+        }
+    }
+};
diff --git a/packages/protobuf/tests/load-definitions.test.ts b/packages/protobuf/tests/load-definitions.test.ts
new file mode 100644
index 00000000000..ab61b93c40b
--- /dev/null
+++ b/packages/protobuf/tests/load-definitions.test.ts
@@ -0,0 +1,100 @@
+import * as ProtoBuf from 'protobufjs/light';
+
+import { loadDefinitions } from '../src/load-definitions';
+
+describe('loadDefinitions', () => {
+    const createProtobufRoot = () => {
+        return ProtoBuf.Root.fromJSON({
+            nested: {
+                MessageType: {
+                    values: {
+                        Initialize: 0,
+                    },
+                },
+            },
+        });
+    };
+
+    it('merge MessageType enum', async () => {
+        const root = createProtobufRoot();
+        await loadDefinitions(root, 'bitcoin', () => {
+            return Promise.resolve({
+                MessageType: {
+                    values: {
+                        GetAddress: 29,
+                    },
+                },
+            });
+        });
+
+        const messageType = root.lookupEnum('MessageType')?.values;
+        expect(messageType).toEqual({
+            Initialize: 0,
+            GetAddress: 29,
+        });
+    });
+
+    it('throw on merge MessageType enum', async () => {
+        const root1 = createProtobufRoot();
+        await expect(
+            loadDefinitions(root1, 'bitcoin', () => {
+                return Promise.resolve({
+                    MessageType: {
+                        values: {
+                            GetAddress: 0,
+                        },
+                    },
+                });
+            }),
+        ).rejects.toThrow('duplicate id 0');
+        expect(root1.lookup('bitcoin')).toBe(null);
+
+        await expect(
+            loadDefinitions(createProtobufRoot(), 'bitcoin', () => {
+                return Promise.resolve({
+                    MessageType: {
+                        values: {
+                            Initialize: 1,
+                        },
+                    },
+                });
+            }),
+        ).rejects.toThrow('duplicate name');
+    });
+
+    it('create MessageType enum', async () => {
+        const root = createProtobufRoot();
+        root.remove(root.lookupEnum('MessageType'));
+
+        await loadDefinitions(root, 'bitcoin', () => {
+            return Promise.resolve({
+                MessageType: {
+                    values: {
+                        GetAddress: 29,
+                    },
+                },
+            });
+        });
+
+        const messageType = root.lookupEnum('MessageType')?.values;
+        expect(messageType).toEqual({
+            GetAddress: 29,
+        });
+    });
+
+    it('already loaded', async () => {
+        const root = createProtobufRoot();
+        root.define('bitcoin', {
+            MessageType: {
+                values: {
+                    GetAddress: 29,
+                },
+            },
+        });
+
+        const spy = jest.fn();
+        await loadDefinitions(root, 'bitcoin', spy);
+
+        expect(spy).toHaveBeenCalledTimes(0);
+    });
+});