diff --git a/src/ConfigCat.Client.Tests/ConfigCacheTests.cs b/src/ConfigCat.Client.Tests/ConfigCacheTests.cs
index 5631c51a..8c46a2fc 100644
--- a/src/ConfigCat.Client.Tests/ConfigCacheTests.cs
+++ b/src/ConfigCat.Client.Tests/ConfigCacheTests.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
@@ -227,6 +228,25 @@ public async Task ConfigCache_ShouldHandleWhenExternalCacheFails(bool isAsync)
         loggerMock.Verify(l => l.Log(LogLevel.Error, 2200, ref It.Ref<FormattableLogMessage>.IsAny, It.Is<Exception>(ex => ex is ApplicationException)), Times.Once);
     }
 
+    [DataRow("test1", "147c5b4c2b2d7c77e1605b1a4309f0ea6684a0c6")]
+    [DataRow("test2", "c09513b1756de9e4bc48815ec7a142b2441ed4d5")]
+    [DataTestMethod]
+    public void CacheKeyGeneration_ShouldBePlatformIndependent(string sdkKey, string expectedCacheKey)
+    {
+        Assert.AreEqual(expectedCacheKey, ConfigCatClient.GetCacheKey(sdkKey));
+    }
+
+    private const string PayloadTestConfigJson = "{\"p\":{\"u\":\"https://cdn-global.configcat.com\",\"r\":0},\"f\":{\"testKey\":{\"v\":\"testValue\",\"t\":1,\"p\":[],\"r\":[]}}}";
+    [DataRow(PayloadTestConfigJson, "2023-06-14T15:27:15.8440000Z", "test-etag", "1686756435844\ntest-etag\n" + PayloadTestConfigJson)]
+    [DataTestMethod]
+    public void CachePayloadSerialization_ShouldBePlatformIndependent(string configJson, string timeStamp, string httpETag, string expectedPayload)
+    {
+        var timeStampDateTime = DateTimeOffset.ParseExact(timeStamp, "o", CultureInfo.InvariantCulture).UtcDateTime;
+        var pc = new ProjectConfig(configJson, configJson.Deserialize<SettingsWithPreferences>(), timeStampDateTime, httpETag);
+
+        Assert.AreEqual(expectedPayload, ProjectConfig.Serialize(pc));
+    }
+
     private sealed class FakeExternalCache : IConfigCatCache
     {
         public volatile string? CachedValue = null;
diff --git a/src/ConfigCatClient/ConfigCatClient.cs b/src/ConfigCatClient/ConfigCatClient.cs
index e98812ae..2cd7cba9 100644
--- a/src/ConfigCatClient/ConfigCatClient.cs
+++ b/src/ConfigCatClient/ConfigCatClient.cs
@@ -664,7 +664,7 @@ private static IConfigService DetermineConfigService(PollingMode pollingMode, Ht
         };
     }
 
-    private static string GetCacheKey(string sdkKey)
+    internal static string GetCacheKey(string sdkKey)
     {
         var key = $"{sdkKey}_{ConfigCatClientOptions.ConfigFileName}_{ProjectConfig.SerializationFormatVersion}";
         return key.Hash();