diff --git a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
index 69c9eb6e99..8462c83994 100644
--- a/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonParserTest.cs
@@ -553,7 +553,7 @@ namespace Google.Protobuf
         [Test]
         // Skip these test cases in .NET 5 because floating point parsing supports bigger values.
         // These big values won't throw an error in the test.
-#if !NET5_0
+#if !NETCOREAPP3_1_OR_GREATER
         [TestCase("1.7977e308")]
         [TestCase("-1.7977e308")]
         [TestCase("1e309")]
diff --git a/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs b/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs
index 0cbc0a4ff8..7cc5c6bcfb 100644
--- a/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs
+++ b/csharp/src/Google.Protobuf.Test/JsonTokenizerTest.cs
@@ -201,7 +201,7 @@ namespace Google.Protobuf
         [TestCase("--1")]
         // Skip these test cases in .NET 5 because floating point parsing supports bigger values.
         // These big values won't throw an error in the test.
-#if !NET5_0
+#if !NETCOREAPP3_1_OR_GREATER
         [TestCase("-1.7977e308")]
         [TestCase("1.7977e308")]
 #endif