diff --git a/examples/src/basic-usage-async-await.js b/examples/src/basic-usage-async-await.js
index c77bb57..f6e478c 100644
--- a/examples/src/basic-usage-async-await.js
+++ b/examples/src/basic-usage-async-await.js
@@ -10,8 +10,8 @@ require('dotenv').config()
 
 // ======== Preparation ======== //
 const conn = new driver.Connection('https://example.com/api/v1/', {
-    header1: header1_value,
-    header2: header2_value
+    header1: 'header1_value',
+    header2: 'header2_value'
 })
 
 const alice = new driver.Ed25519Keypair()
diff --git a/examples/src/basic-usage.js b/examples/src/basic-usage.js
index 6b45d64..56520e8 100644
--- a/examples/src/basic-usage.js
+++ b/examples/src/basic-usage.js
@@ -10,8 +10,8 @@ require('dotenv').config()
 
 // ======== Preparation ======== //
 const conn = new driver.Connection('https://example.com/api/v1/', {
-    header1: header1_value,
-    header2: header2_value
+    header1: 'header1_value',
+    header2: 'header2_value'
 })
 
 const alice = new driver.Ed25519Keypair()
diff --git a/examples/src/query-assets.js b/examples/src/query-assets.js
index a77f5f0..29dd23d 100644
--- a/examples/src/query-assets.js
+++ b/examples/src/query-assets.js
@@ -10,8 +10,8 @@ require('dotenv').config()
 
 // ======== Preparation ======== //
 const conn = new driver.Connection('https://example.com/api/v1/', {
-    header1: header1_value,
-    header2: header2_value
+    header1: 'header1_value',
+    header2: 'header2_value'
 })
 
 const alice = new driver.Ed25519Keypair()