diff --git a/MoreLinq.Test/AggregateTest.cs b/MoreLinq.Test/AggregateTest.cs
index 9ef7b2336..04ec29154 100644
--- a/MoreLinq.Test/AggregateTest.cs
+++ b/MoreLinq.Test/AggregateTest.cs
@@ -26,6 +26,7 @@ namespace MoreLinq.Test
     using System.Reactive.Linq;
     using System.Reflection;
     using NUnit.Framework.Interfaces;
+    using static MoreLinq.Extensions.AppendExtension;
     using static FuncModule;
 
     [TestFixture]
diff --git a/MoreLinq.Test/AppendTest.cs b/MoreLinq.Test/AppendTest.cs
index 55ff31597..58dbd6c9d 100644
--- a/MoreLinq.Test/AppendTest.cs
+++ b/MoreLinq.Test/AppendTest.cs
@@ -15,12 +15,11 @@
 // limitations under the License.
 #endregion
 
-#if !NET471_OR_GREATER && !NETSTANDARD1_6_OR_GREATER && !NETCOREAPP2_0_OR_GREATER
-
 namespace MoreLinq.Test
 {
     using System.Collections.Generic;
     using NUnit.Framework;
+    using static MoreLinq.Extensions.AppendExtension;
 
     [TestFixture]
     public class AppendTest
@@ -92,5 +91,3 @@ public void AppendWithSharedSource()
         }
     }
 }
-
-#endif
diff --git a/MoreLinq.Test/DistinctByTest.cs b/MoreLinq.Test/DistinctByTest.cs
index 377c9a318..70c684592 100644
--- a/MoreLinq.Test/DistinctByTest.cs
+++ b/MoreLinq.Test/DistinctByTest.cs
@@ -15,12 +15,11 @@
 // limitations under the License.
 #endregion
 
-#if !NET6_0_OR_GREATER
-
 namespace MoreLinq.Test
 {
     using System;
     using NUnit.Framework;
+    using static MoreLinq.Extensions.DistinctByExtension;
 
     [TestFixture]
     public class DistinctByTest
@@ -63,5 +62,3 @@ public void DistinctByIsLazyWithComparer()
         }
     }
 }
-
-#endif
diff --git a/MoreLinq.Test/Enumerable.cs b/MoreLinq.Test/Enumerable.cs
index ae22e31cd..f7795af4e 100644
--- a/MoreLinq.Test/Enumerable.cs
+++ b/MoreLinq.Test/Enumerable.cs
@@ -45,11 +45,6 @@ public static bool Any<TSource>(this IEnumerable<TSource> source) =>
         public static bool Any<TSource>(this IEnumerable<TSource> source, Func<TSource, bool> predicate) =>
             LinqEnumerable.Any(source, predicate);
 
-#if NET471_OR_GREATER || NET6_0_OR_GREATER
-        public static IEnumerable<TSource> Append<TSource> (this IEnumerable<TSource> source, TSource element) =>
-            LinqEnumerable.Append(source, element);
-#endif
-
         public static IEnumerable<TSource> AsEnumerable<TSource>(this IEnumerable<TSource> source) =>
             LinqEnumerable.AsEnumerable(source);
 
diff --git a/MoreLinq.Test/GroupAdjacentTest.cs b/MoreLinq.Test/GroupAdjacentTest.cs
index d6da9909a..b3830a2d2 100644
--- a/MoreLinq.Test/GroupAdjacentTest.cs
+++ b/MoreLinq.Test/GroupAdjacentTest.cs
@@ -20,6 +20,7 @@ namespace MoreLinq.Test
     using System;
     using System.Collections.Generic;
     using NUnit.Framework;
+    using static MoreLinq.Extensions.AppendExtension;
 
     [TestFixture]
     public class GroupAdjacentTest
diff --git a/MoreLinq.Test/PartialSortTest.cs b/MoreLinq.Test/PartialSortTest.cs
index a838efdc3..555428fad 100644
--- a/MoreLinq.Test/PartialSortTest.cs
+++ b/MoreLinq.Test/PartialSortTest.cs
@@ -19,6 +19,7 @@ namespace MoreLinq.Test
 {
     using System;
     using NUnit.Framework;
+    using static MoreLinq.Extensions.AppendExtension;
 
     [TestFixture]
     public class PartialSortTests
diff --git a/MoreLinq.Test/PrependTest.cs b/MoreLinq.Test/PrependTest.cs
index 3a4f938d1..de8253f6e 100644
--- a/MoreLinq.Test/PrependTest.cs
+++ b/MoreLinq.Test/PrependTest.cs
@@ -15,13 +15,12 @@
 // limitations under the License.
 #endregion
 
-#if !NET471_OR_GREATER && !NETSTANDARD1_6_OR_GREATER && !NETCOREAPP2_0_OR_GREATER
-
 namespace MoreLinq.Test
 {
     using System.Collections.Generic;
     using NUnit.Framework;
     using NUnit.Framework.Interfaces;
+    using static MoreLinq.Extensions.PrependExtension;
 
     [TestFixture]
     public class PrependTest
@@ -91,5 +90,3 @@ public void PrependWithSharedSource()
         }
     }
 }
-
-#endif
diff --git a/MoreLinq.Test/SkipLastTest.cs b/MoreLinq.Test/SkipLastTest.cs
index f6bbf7796..94187ef75 100644
--- a/MoreLinq.Test/SkipLastTest.cs
+++ b/MoreLinq.Test/SkipLastTest.cs
@@ -15,12 +15,11 @@
 // limitations under the License.
 #endregion
 
-#if !NETSTANDARD2_1 && !NETCOREAPP2_0_OR_GREATER
-
 namespace MoreLinq.Test
 {
     using System.Collections.Generic;
     using NUnit.Framework;
+    using static MoreLinq.Extensions.SkipLastExtension;
 
     [TestFixture]
     public class SkipLastTest
@@ -70,5 +69,3 @@ public void SkipLastUsesCollectionCountAtIterationTime()
         }
     }
 }
-
-#endif
diff --git a/MoreLinq.Test/TakeLastTest.cs b/MoreLinq.Test/TakeLastTest.cs
index fc0347bf6..2c20f8137 100644
--- a/MoreLinq.Test/TakeLastTest.cs
+++ b/MoreLinq.Test/TakeLastTest.cs
@@ -15,13 +15,12 @@
 // limitations under the License.
 #endregion
 
-#if !NETSTANDARD2_1 && !NETCOREAPP2_0_OR_GREATER
-
 namespace MoreLinq.Test
 {
     using NUnit.Framework;
     using System.Collections.Generic;
     using System;
+    using static MoreLinq.Extensions.TakeLastExtension;
 
     [TestFixture]
     public class TakeLastTest
@@ -91,5 +90,3 @@ static void AssertTakeLast<T>(ICollection<T> input, int count, Action<IEnumerabl
         }
     }
 }
-
-#endif