diff --git a/src/IF.Lastfm.Core.Tests/Api/LastAuthTests.cs b/src/IF.Lastfm.Core.Tests/Api/LastAuthTests.cs
new file mode 100644
index 0000000..4730e17
--- /dev/null
+++ b/src/IF.Lastfm.Core.Tests/Api/LastAuthTests.cs
@@ -0,0 +1,34 @@
+using IF.Lastfm.Core.Api;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System.Collections.Generic;
+
+namespace IF.Lastfm.Core.Tests.Api
+{
+    [TestClass]
+    public class LastAuthTests
+    {
+        private ILastAuth _auth;
+
+        [TestInitialize]
+        public void Initialise()
+        {
+            _auth = new LastAuth("user", "pass");
+        }
+
+        [TestMethod]
+        public void GeneratesCorrectMethodSignature()
+        {
+            const string method = "test.method";
+            var parameters = new Dictionary<string, string>
+            {
+                {"test", "value"},
+                {"test2", "value2"}
+            };
+
+            const string expectedHash = "910231882F8AA6D4BBACB7C5FE5F5CC8";
+            var actual = _auth.GenerateMethodSignature(method, parameters);
+
+            Assert.AreEqual(expectedHash, actual);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/IF.Lastfm.Core.Tests/IF.Lastfm.Core.Tests.csproj b/src/IF.Lastfm.Core.Tests/IF.Lastfm.Core.Tests.csproj
index d0c1160..03a6bdb 100644
--- a/src/IF.Lastfm.Core.Tests/IF.Lastfm.Core.Tests.csproj
+++ b/src/IF.Lastfm.Core.Tests/IF.Lastfm.Core.Tests.csproj
@@ -84,6 +84,7 @@
     <Compile Include="Api\Commands\UserApi\UserGetRecentTracksCommandTests.cs" />
     <Compile Include="Api\Commands\UserApi\GetTrackShoutsCommandTests.cs" />
     <Compile Include="Api\Helpers\ApiHelperTests.cs" />
+    <Compile Include="Api\LastAuthTests.cs" />
     <Compile Include="Api\MockAlbumApi.cs" />
     <Compile Include="MockLastFm.cs" />
     <Compile Include="LastFmTests.cs" />