diff --git a/src/utils/ConfigHelper.ts b/src/utils/ConfigHelper.ts
index f49575f7..ebcb0360 100644
--- a/src/utils/ConfigHelper.ts
+++ b/src/utils/ConfigHelper.ts
@@ -1,7 +1,7 @@
 import Config from '../models/Config'
 
 export interface ConfigHelperConfig extends Config {
-  chainId?: number
+  chainId: 1 | 4 | number
   network: 'mainnet' | 'rinkeby' | 'development' | string
 }
 
diff --git a/test/unit/utils/ConfigHelper.test.ts b/test/unit/utils/ConfigHelper.test.ts
new file mode 100644
index 00000000..a36962ac
--- /dev/null
+++ b/test/unit/utils/ConfigHelper.test.ts
@@ -0,0 +1,23 @@
+import { assert } from 'chai'
+import { ConfigHelper } from '../../../src/lib'
+
+describe('ConfigHelper', () => {
+  it('should get config based on network name', () => {
+    const network = 'rinkeby'
+    const config = new ConfigHelper().getConfig(network)
+    assert(config.network === network)
+  })
+
+  it('should get config based on network name, and add passed Infura ID', () => {
+    const network = 'rinkeby'
+    const infuraId = 'helloInfura'
+    const config = new ConfigHelper().getConfig(network, infuraId)
+    assert(config.nodeUri.includes(infuraId))
+  })
+
+  it('should get config based on chain ID', () => {
+    const chainId = 4
+    const config = new ConfigHelper().getConfigById(chainId)
+    assert(config.chainId === chainId)
+  })
+})