diff --git a/src/Splitio/Domain/EvaluationOptions.cs b/src/Splitio/Domain/EvaluationOptions.cs
new file mode 100644
index 00000000..e4e9e0f3
--- /dev/null
+++ b/src/Splitio/Domain/EvaluationOptions.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace Splitio.Domain
+{
+    public class EvaluationOptions
+    {
+        public Dictionary<string, object> Properties { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/Splitio/Domain/KeyImpression.cs b/src/Splitio/Domain/KeyImpression.cs
index 92712456..a6b033e6 100644
--- a/src/Splitio/Domain/KeyImpression.cs
+++ b/src/Splitio/Domain/KeyImpression.cs
@@ -33,5 +33,6 @@ public KeyImpression(string matchingKey, string feature, string treatment, long
         public bool Optimized { get; set; }
         [JsonIgnore]
         public bool ImpressionsDisabled { get; set; }
+        public string Properties { get; set; }
     }
 }