diff --git a/contentstack.model.generator.tests/OAuthServiceTests.cs b/contentstack.model.generator.tests/OAuthServiceTests.cs
index 356370e..fcd69cd 100644
--- a/contentstack.model.generator.tests/OAuthServiceTests.cs
+++ b/contentstack.model.generator.tests/OAuthServiceTests.cs
@@ -5,7 +5,6 @@
 using contentstack.CMA;
 using contentstack.CMA.OAuth;
 using System.Net.Http;
-using Newtonsoft.Json;
 using System.Collections.Generic;
 
 namespace contentstack.model.generator.tests
diff --git a/contentstack.model.generator.tests/OAuthTokenExchangeTests.cs b/contentstack.model.generator.tests/OAuthTokenExchangeTests.cs
index d16a597..5b8fbb3 100644
--- a/contentstack.model.generator.tests/OAuthTokenExchangeTests.cs
+++ b/contentstack.model.generator.tests/OAuthTokenExchangeTests.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Text.Json;
 using contentstack.CMA.OAuth;
 using Xunit;
 
@@ -61,8 +62,9 @@ public void OAuthTokenResponse_ShouldBeSerializable()
             };
 
             
-            var json = Newtonsoft.Json.JsonConvert.SerializeObject(response);
-            var deserializedResponse = Newtonsoft.Json.JsonConvert.DeserializeObject<OAuthTokenResponse>(json);
+            var json = JsonSerializer.Serialize(response);
+            var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+            var deserializedResponse = JsonSerializer.Deserialize<OAuthTokenResponse>(json, options);
 
             
             Assert.NotNull(deserializedResponse);
diff --git a/contentstack.model.generator/CMA/OAuth/OAuthService.cs b/contentstack.model.generator/CMA/OAuth/OAuthService.cs
index 55ae9fa..b3499ef 100644
--- a/contentstack.model.generator/CMA/OAuth/OAuthService.cs
+++ b/contentstack.model.generator/CMA/OAuth/OAuthService.cs
@@ -4,7 +4,7 @@
 using System.Security.Cryptography;
 using System.Text;
 using System.Threading.Tasks;
-using Newtonsoft.Json;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace contentstack.CMA.OAuth
@@ -171,14 +171,15 @@ public static async Task<OAuthTokenResponse> ExchangeCodeForTokenAsync(Contentst
                 
                 // Parse response
                 string responseContent = await response.Content.ReadAsStringAsync();
-                var tokenResponse = JsonConvert.DeserializeObject<OAuthTokenResponse>(responseContent);
-                
+                var serializerOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+                var tokenResponse = JsonSerializer.Deserialize<OAuthTokenResponse>(responseContent, serializerOptions);
+
                 // Set expiration time if not already set
                 if (tokenResponse.ExpiresAt == default(DateTime) && tokenResponse.ExpiresIn > 0)
                 {
                     tokenResponse.ExpiresAt = DateTime.UtcNow.AddSeconds(tokenResponse.ExpiresIn);
                 }
-                
+
                 return tokenResponse;
             }
         }
@@ -231,8 +232,9 @@ public static async Task<OAuthTokenResponse> RefreshTokenAsync(ContentstackOptio
                 
                 // Parse response
                 string responseContent = await response.Content.ReadAsStringAsync();
-                var tokenResponse = JsonConvert.DeserializeObject<OAuthTokenResponse>(responseContent);
-                
+                var serializerOptions = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
+                var tokenResponse = JsonSerializer.Deserialize<OAuthTokenResponse>(responseContent, serializerOptions);
+
                 // Set expiration time if not already set
                 if (tokenResponse.ExpiresAt == default(DateTime) && tokenResponse.ExpiresIn > 0)
                 {