diff --git a/PolyShim/NetCore30/MemberNotNullAttribute.cs b/PolyShim/Net50/MemberNotNullAttribute.cs
similarity index 83%
rename from PolyShim/NetCore30/MemberNotNullAttribute.cs
rename to PolyShim/Net50/MemberNotNullAttribute.cs
index b63c323..3a7537e 100644
--- a/PolyShim/NetCore30/MemberNotNullAttribute.cs
+++ b/PolyShim/Net50/MemberNotNullAttribute.cs
@@ -1,4 +1,4 @@
-#if (NETCOREAPP && !NETCOREAPP3_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD && !NETSTANDARD2_1_OR_GREATER)
+#if (NETCOREAPP && !NET5_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
 #nullable enable
 // ReSharper disable RedundantUsingDirective
 // ReSharper disable CheckNamespace
diff --git a/PolyShim/NetCore30/MemberNotNullWhenAttribute.cs b/PolyShim/Net50/MemberNotNullWhenAttribute.cs
similarity index 85%
rename from PolyShim/NetCore30/MemberNotNullWhenAttribute.cs
rename to PolyShim/Net50/MemberNotNullWhenAttribute.cs
index 26ae834..31606c1 100644
--- a/PolyShim/NetCore30/MemberNotNullWhenAttribute.cs
+++ b/PolyShim/Net50/MemberNotNullWhenAttribute.cs
@@ -1,4 +1,4 @@
-#if (NETCOREAPP && !NETCOREAPP3_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD && !NETSTANDARD2_1_OR_GREATER)
+#if (NETCOREAPP && !NET5_0_OR_GREATER) || (NETFRAMEWORK) || (NETSTANDARD)
 #nullable enable
 // ReSharper disable RedundantUsingDirective
 // ReSharper disable CheckNamespace