diff --git a/Microsoft.Azure.Cosmos/src/CosmosElements/CosmosElementJsonConverter.cs b/Microsoft.Azure.Cosmos/src/CosmosElements/CosmosElementJsonConverter.cs
index bd1ef99945..8073ea6641 100644
--- a/Microsoft.Azure.Cosmos/src/CosmosElements/CosmosElementJsonConverter.cs
+++ b/Microsoft.Azure.Cosmos/src/CosmosElements/CosmosElementJsonConverter.cs
@@ -84,7 +84,7 @@ public override bool CanConvert(Type objectType)
 #endif
         }
 
-        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        public override object ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
         {
             JToken token = JToken.Load(reader);
             string json = JsonConvert.SerializeObject(token);
@@ -92,7 +92,7 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
             return CosmosElement.CreateFromBuffer(buffer);
         }
 
-        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
         {
             NewtonsoftToCosmosDBWriter writerInterop = NewtonsoftToCosmosDBWriter.CreateFromWriter(writer);
 
diff --git a/Microsoft.Azure.Cosmos/src/Microsoft.Azure.Cosmos.csproj b/Microsoft.Azure.Cosmos/src/Microsoft.Azure.Cosmos.csproj
index 43481ba715..632d1756f8 100644
--- a/Microsoft.Azure.Cosmos/src/Microsoft.Azure.Cosmos.csproj
+++ b/Microsoft.Azure.Cosmos/src/Microsoft.Azure.Cosmos.csproj
@@ -159,6 +159,7 @@
 
 	<ItemGroup Condition=" '$(ProjectRef)' != 'True' ">
 		<PackageReference Include="Microsoft.HybridRow" Version="[$(HybridRowVersion)]" PrivateAssets="All" />
+		<PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
 	</ItemGroup>
 
diff --git a/Microsoft.Azure.Cosmos/src/Resource/FullFidelity/ChangeFeedMetadata.cs b/Microsoft.Azure.Cosmos/src/Resource/FullFidelity/ChangeFeedMetadata.cs
index 1dae4f1e1b..dc4a5b1150 100644
--- a/Microsoft.Azure.Cosmos/src/Resource/FullFidelity/ChangeFeedMetadata.cs
+++ b/Microsoft.Azure.Cosmos/src/Resource/FullFidelity/ChangeFeedMetadata.cs
@@ -27,7 +27,7 @@ class ChangeFeedMetadata
         /// The change's conflict resolution timestamp.
         /// </summary>
         [JsonProperty(PropertyName = ChangeFeedMetadataFields.ConflictResolutionTimestamp, NullValueHandling = NullValueHandling.Ignore)]
-        [JsonConverter(typeof(UnixDateTimeConverter))]
+        [JsonConverter(typeof(Documents.UnixDateTimeConverter))]
         public DateTime ConflictResolutionTimestamp { get; internal set; }
 
         /// <summary>