diff --git a/src/sdk/USStreetApi/Client.cs b/src/sdk/USStreetApi/Client.cs
index fe8e710..09248a6 100644
--- a/src/sdk/USStreetApi/Client.cs
+++ b/src/sdk/USStreetApi/Client.cs
@@ -72,8 +72,7 @@ private static void PopulateQueryString(Lookup address, Request request)
 			if (address.MaxCandidates != 1) 
 				request.SetParameter("candidates", address.MaxCandidates.ToString(CultureInfo.InvariantCulture));
 			
-			if (address.GetFormatString() != "default")
-				request.SetParameter("format", address.GetFormatString());
+			request.SetParameter("format", address.OutputFormat);
 		}
 
 		private static void AssignCandidatesToLookups(Batch batch, IEnumerable<Candidate> candidates)
diff --git a/src/sdk/USStreetApi/Lookup.cs b/src/sdk/USStreetApi/Lookup.cs
index a12ddcf..95a6ad3 100644
--- a/src/sdk/USStreetApi/Lookup.cs
+++ b/src/sdk/USStreetApi/Lookup.cs
@@ -15,12 +15,9 @@ public class Lookup : ILookup
 		public const string ENHANCED = "enhanced";
 		public const string INVALID = "invalid";
 		public const string RANGE = "range"; // Deprecated
-		
-		public enum Format
-		{
-			Default,
-			ProjectUsa,
-		}
+
+		public const string DEFAULT_FORMAT = "default";
+		public const string PROJECT_USA_FORMAT = "project-usa";
 		
 		public List<Candidate> Result { get; private set; }
 
@@ -61,7 +58,7 @@ public enum Format
 		public string MatchStrategy { get; set; }
 
 		[DataMember(Name = "format")]
-		public Format OutputFormat { get; set; }
+		public string OutputFormat { get; set; }
 		
 		public int MaxCandidates
 		{
@@ -96,18 +93,5 @@ public void AddToResult(Candidate newCandidate)
 		{
 			this.Result.Add(newCandidate);
 		}
-		
-		public string GetFormatString()
-		{
-			switch (this.OutputFormat)
-			{
-				case Format.Default:
-					return "default";
-				case Format.ProjectUsa:
-					return "project-usa";
-				default:
-					return "";
-			}
-		}
 	}
 }
\ No newline at end of file
diff --git a/src/tests/USStreetApi/ClientTests.cs b/src/tests/USStreetApi/ClientTests.cs
index b041823..1a69d73 100644
--- a/src/tests/USStreetApi/ClientTests.cs
+++ b/src/tests/USStreetApi/ClientTests.cs
@@ -67,7 +67,7 @@ public void TestSendingSingleFullyPopulatedLookupWithFormatOutput()
 				ZipCode = "7",
 				Lastline = "8",
 				MatchStrategy = "enhanced",
-				OutputFormat = Lookup.Format.ProjectUsa
+				OutputFormat = Lookup.PROJECT_USA_FORMAT
 			};
 
 			client.Send(lookup);