diff --git a/NMoneys.nuspec b/NMoneys.nuspec
index c8fa4dd..fa2f271 100644
--- a/NMoneys.nuspec
+++ b/NMoneys.nuspec
@@ -3,7 +3,7 @@
 	<metadata xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
 		<id>NMoneys</id>
 		<title>NMoneys</title>
-		<version>5.1.0.0</version>
+		<version>5.1.1.0</version>
 		<authors>Daniel González García</authors>
 		<licenseUrl>http://www.opensource.org/licenses/bsd-license.php</licenseUrl>
 		<requireLicenseAcceptance>false</requireLicenseAcceptance>
diff --git a/src/NMoneys.Tests/CurrencyTester.cs b/src/NMoneys.Tests/CurrencyTester.cs
index 979a134..0cc9840 100644
--- a/src/NMoneys.Tests/CurrencyTester.cs
+++ b/src/NMoneys.Tests/CurrencyTester.cs
@@ -155,11 +155,6 @@ public void ObsoleteCurrencies_AreConsistent()
 
 			// all currency codes are marked as obsolete
 			Assert.That(obsoleteCodes, Has.All.Matches<CurrencyIsoCode>(Enumeration.HasAttribute<CurrencyIsoCode, ObsoleteAttribute>));
-
-			// there no more currency codes marked as obsolete than obsolete currencies
-			Assert.That(obsoleteCodes, Is.EquivalentTo(
-				Enumeration.GetValues<CurrencyIsoCode>()
-					.Where(Enumeration.HasAttribute<CurrencyIsoCode, ObsoleteAttribute>)));
 		}
 
 #pragma warning restore 169
diff --git a/src/NMoneys/Currencies.xml b/src/NMoneys/Currencies.xml
index fd173ef..38e50ae 100644
--- a/src/NMoneys/Currencies.xml
+++ b/src/NMoneys/Currencies.xml
@@ -289,6 +289,7 @@
 		<groupSizes>3</groupSizes>
 		<positivePattern>3</positivePattern>
 		<negativePattern>8</negativePattern>
+		<obsolete>true</obsolete>
 	</currency>
 	<currency code="BZD">
 		<englishName>Belize Dollar</englishName>
diff --git a/src/NMoneys/CurrencyIsoCode.cs b/src/NMoneys/CurrencyIsoCode.cs
index 2bf0ff6..f3d89f8 100644
--- a/src/NMoneys/CurrencyIsoCode.cs
+++ b/src/NMoneys/CurrencyIsoCode.cs
@@ -142,7 +142,7 @@ public enum CurrencyIsoCode : short
 		/// <summary>
 		/// Belarussian Ruble
 		/// </summary>
-		[EnumMember, CanonicalCulture("be-BY")]
+		[EnumMember, CanonicalCulture("be-BY"), Obsolete("deprecated in favor of BYN")]
 		BYR = 974,
 		/// <summary>
 		/// Belize Dollar
diff --git a/src/NMoneys/ObsoleteCurrencies.cs b/src/NMoneys/ObsoleteCurrencies.cs
index 21a9f42..5c36792 100644
--- a/src/NMoneys/ObsoleteCurrencies.cs
+++ b/src/NMoneys/ObsoleteCurrencies.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.Contracts;
+using System.Linq;
 using NMoneys.Support;
 
 namespace NMoneys
@@ -13,15 +14,12 @@ internal static class ObsoleteCurrencies
 		private static readonly HashSet<CurrencyIsoCode> _set;
 		static ObsoleteCurrencies()
 		{
-#pragma warning disable 612,618
-			_set = new HashSet<CurrencyIsoCode>(FastEnumComparer<CurrencyIsoCode>.Instance)
-			{
-				CurrencyIsoCode.EEK,
-				CurrencyIsoCode.ZMK,
-				CurrencyIsoCode.LVL,
-				CurrencyIsoCode.LTL,
-			};
-#pragma warning restore 612,618
+			var obsoleteCodes = Enumeration.GetValues<CurrencyIsoCode>()
+				.Where(Enumeration.HasAttribute<CurrencyIsoCode, ObsoleteAttribute>);
+
+			_set = new HashSet<CurrencyIsoCode>(
+				obsoleteCodes,
+				FastEnumComparer<CurrencyIsoCode>.Instance);
 		}
 
 		[Pure]
@@ -37,6 +35,6 @@ public static bool IsObsolete(Currency currency)
 		}
 
 		[Pure]
-		public static uint Count => Convert.ToUInt32(_set.Count);
+		public static ushort Count => Convert.ToUInt16(_set.Count);
 	}
 }
\ No newline at end of file
diff --git a/src/NMoneys/Properties/NMoneys_AssemblyInfo.cs b/src/NMoneys/Properties/NMoneys_AssemblyInfo.cs
index 01cc6c0..11c274d 100644
--- a/src/NMoneys/Properties/NMoneys_AssemblyInfo.cs
+++ b/src/NMoneys/Properties/NMoneys_AssemblyInfo.cs
@@ -26,5 +26,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("5.1.0.0")]
-[assembly: AssemblyFileVersion("5.1.0.0")]
\ No newline at end of file
+[assembly: AssemblyVersion("5.1.1.0")]
+[assembly: AssemblyFileVersion("5.1.1.0")]
\ No newline at end of file