diff --git a/src/Tests/Microsoft.NET.TestFramework/EnvironmentInfo.cs b/src/Tests/Microsoft.NET.TestFramework/EnvironmentInfo.cs
index cf0af4fdb79e..37dc94829f68 100644
--- a/src/Tests/Microsoft.NET.TestFramework/EnvironmentInfo.cs
+++ b/src/Tests/Microsoft.NET.TestFramework/EnvironmentInfo.cs
@@ -125,9 +125,9 @@ public static bool SupportsTargetFramework(string targetFramework)
             {
                 string restOfRid = currentRid.Substring(ridOS.Length + 1);
                 string ubuntuVersionString = restOfRid.Split('-')[0];
-                if (float.TryParse(ubuntuVersionString, out float ubuntuVersion))
+                if (float.TryParse(ubuntuVersionString, System.Globalization.CultureInfo.InvariantCulture, out float ubuntuVersion))
                 {
-                    if (ubuntuVersion > 16.04)
+                    if (ubuntuVersion > 16.04f)
                     {
                         if (nugetFramework.Version < new Version(2, 0, 0, 0))
                         {
@@ -144,27 +144,25 @@ public static bool SupportsTargetFramework(string targetFramework)
             {
                 string restOfRid = currentRid.Substring(ridOS.Length + 1);
                 string osxVersionString = restOfRid.Split('-')[0];
-                //  From a string such as "10.14", get the second part, e.g. "14"
-                string osxVersionString2 = osxVersionString.Split('.')[1];
-                if (int.TryParse(osxVersionString2, out int osxVersion))
+                if (float.TryParse(osxVersionString, System.Globalization.CultureInfo.InvariantCulture, out float osxVersion))
                 {
                     //  .NET Core 1.1 - 10.11, 10.12
                     //  .NET Core 2.0 - 10.12+
-                    if (osxVersion <= 11)
+                    if (osxVersion <= 10.11f)
                     {
                         if (nugetFramework.Version >= new Version(2, 0, 0, 0))
                         {
                             return false;
                         }
                     }
-                    else if (osxVersion == 12)
+                    else if (osxVersion == 10.12f)
                     {
                         if (nugetFramework.Version < new Version(2, 0, 0, 0))
                         {
                             return false;
                         }
                     }
-                    else if (osxVersion > 12)
+                    else if (osxVersion > 10.12f)
                     {
                         //  .NET Core 2.0 is out of support, and doesn't seem to work with OS X 10.14
                         //  (it finds no assets for the RID), even though the support page says "10.12+"