diff --git a/Meade.net.Telescope.UnitTests/TelescopeUnitTests.cs b/Meade.net.Telescope.UnitTests/TelescopeUnitTests.cs
index 8a94096..a088691 100644
--- a/Meade.net.Telescope.UnitTests/TelescopeUnitTests.cs
+++ b/Meade.net.Telescope.UnitTests/TelescopeUnitTests.cs
@@ -2783,6 +2783,8 @@ namespace Meade.net.Telescope.UnitTests
         [TestCase(DriveRates.driveSidereal, "+60.1")]
         [TestCase(DriveRates.driveSolar, "+60.0")]
         [TestCase(DriveRates.driveLunar, "+57.9")]
+        [TestCase(DriveRates.driveLunar, "57.3")]
+        [TestCase(DriveRates.driveLunar, "58.9")]
         public void TrackingRate_Get_WhenConnected_ThenSendsCommandToTelescope(DriveRates rate, string trackingRate)
         {
             _siderealTrackingRate = trackingRate;
diff --git a/Meade.net.Telescope/Meade.net.Telescope.csproj b/Meade.net.Telescope/Meade.net.Telescope.csproj
index a884ce0..f51673b 100644
--- a/Meade.net.Telescope/Meade.net.Telescope.csproj
+++ b/Meade.net.Telescope/Meade.net.Telescope.csproj
@@ -128,6 +128,7 @@
     <Compile Include="Clock.cs" />
     <Compile Include="ComparisonResult.cs" />
     <Compile Include="DoubleExtensions.cs" />
+    <Compile Include="ExtensionMethods\DoubelExtensions.cs" />
     <Compile Include="IClock.cs" />
     <Compile Include="StringExtensions.cs" />
     <Compile Include="Telescope.cs" />
@@ -187,6 +188,7 @@
       <Name>Meade.net</Name>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>
     <PreBuildEvent>
diff --git a/Meade.net.Telescope/Telescope.cs b/Meade.net.Telescope/Telescope.cs
index e7aae54..e417173 100644
--- a/Meade.net.Telescope/Telescope.cs
+++ b/Meade.net.Telescope/Telescope.cs
@@ -2643,25 +2643,20 @@ namespace ASCOM.Meade.net
 
                 rate = rate.Replace("+",  string.Empty);
 
+                var rateDouble = double.Parse(rate);
+
                 DriveRates result;
 
-                switch (rate)
-                {
-                    case "60.1":
-                        result = DriveRates.driveSidereal;
-                        break;
-                    case "60.0":
-                        result = DriveRates.driveSolar;
-                        break;
-                    case "57.9":
-                        result = DriveRates.driveLunar;
-                        break;
-                    default:
-                        result = DriveRates.driveKing;
-                        //If this is ever returned it is representing a fail condition.
-                        break;
-                }
-                
+                if (rateDouble.Equals(60.1))
+                    result = DriveRates.driveSidereal;
+                else if (rateDouble.Equals(60.0))
+                    result = DriveRates.driveSolar;
+                else if (rateDouble.Between(57.3, 58.9))
+                    result = DriveRates.driveLunar;
+                else
+                    //If this is ever returned it is representing a fail condition.
+                    //result = DriveRates.driveKing;
+                    throw new ASCOM.InvalidValueException($"{rate} is not a supported tracking rate for meade mounts");
 
                 LogMessage("TrackingRate Get", $"{rate} {result}");