diff --git a/MarkupString.Tests/Ansi/MarkdownRenderTests.cs b/MarkupString.Tests/Ansi/MarkdownRenderTests.cs
index 8d80669..3802b49 100644
--- a/MarkupString.Tests/Ansi/MarkdownRenderTests.cs
+++ b/MarkupString.Tests/Ansi/MarkdownRenderTests.cs
@@ -298,7 +298,7 @@ public async Task TextTheVocabularyMarksIsKept()
 	[Test]
 	public void PlainTextReadsBackAsItself()
 	{
-		var gen = Gen.OneOfConst(Pieces).Array[0, 12].Select(string.Concat);
+		var gen = Gen.OneOf(Pieces).Array[0, 12].Select(string.Concat);
 		Check.Sample(gen, text =>
 		{
 			var markdown = Render(MarkupText.Plain(text));
@@ -318,7 +318,7 @@ public void PlainTextReadsBackAsItself()
 	public void StyledTextReadsBackAsItsWords()
 	{
 		var styles = new[] { Bold, Italic, AnsiMarkup.Create(strikeThrough: true), AnsiMarkup.Create(bold: true, italic: true) };
-		var gen = Gen.Select(Gen.OneOfConst(Pieces).Array[1, 4].Select(string.Concat), Gen.Int[-1, styles.Length - 1])
+		var gen = Gen.Select(Gen.OneOf(Pieces).Array[1, 4].Select(string.Concat), Gen.Int[-1, styles.Length - 1])
 			.Array[1, 5]
 			.Select(parts => MarkupText.Join(MarkupText.Plain(" "), parts.Select(part => part.Item2 < 0 ? MarkupText.Plain(part.Item1) : MarkupText.Wrap(styles[part.Item2], part.Item1))));
 		Check.Sample(gen, text =>
diff --git a/MarkupString.Tests/MarkupString.Tests.csproj b/MarkupString.Tests/MarkupString.Tests.csproj
index 4a038e1..9c10fe0 100644
--- a/MarkupString.Tests/MarkupString.Tests.csproj
+++ b/MarkupString.Tests/MarkupString.Tests.csproj
@@ -8,11 +8,11 @@
     <NoWarn>TUnit0038;TUnitAssertions0002</NoWarn>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="CsCheck" Version="4.9.1" />
-    <PackageReference Include="TUnit" Version="1.75.0" />
+    <PackageReference Include="CsCheck" Version="5.0.0" />
+    <PackageReference Include="TUnit" Version="1.76.28" />
     <!-- A GitHub-flavoured Markdown reader, so the Markdown tests check what a reader makes of the output
          rather than only the characters written. -->
-    <PackageReference Include="Markdig" Version="1.4.1" />
+    <PackageReference Include="Markdig" Version="1.5.0" />
     <!-- Verify.TUnit carries a floor on TUnit.Core. Bump the two together: if NuGet lifts
          TUnit.Core past the TUnit.Engine this project asks for, the split versions fault at
          startup with MissingFieldException rather than failing to restore. -->
diff --git a/MarkupString.Tests/Properties/RoundTripProperties.cs b/MarkupString.Tests/Properties/RoundTripProperties.cs
index 6821ce4..dcedf69 100644
--- a/MarkupString.Tests/Properties/RoundTripProperties.cs
+++ b/MarkupString.Tests/Properties/RoundTripProperties.cs
@@ -74,7 +74,7 @@ public class RoundTripProperties
 	/// Links are rare (the no-link case is weighted five to one) and cover both kinds, an
 	/// unsafe scheme, a hint, and a target that needs encoding.
 	/// </summary>
-	private static readonly Gen<(string? Url, string? Text, LinkKind Kind)> GenLink = Gen.OneOfConst(
+	private static readonly Gen<(string? Url, string? Text, LinkKind Kind)> GenLink = Gen.OneOf(
 		((string?)null, (string?)null, LinkKind.Url),
 		(null, null, LinkKind.Url),
 		(null, null, LinkKind.Url),
@@ -105,8 +105,8 @@ public class RoundTripProperties
 			clear: flag[8]));
 
 	private static readonly Gen<IMarkup> GenHtmlMarkup = Gen.Select(
-		Gen.OneOfConst("b", "i", "u", "s", "send", "div"),
-		Gen.OneOfConst<string?>(null, null, "class=\"x\"", "href=\"north\" hint=\"Go north\""),
+		Gen.OneOf("b", "i", "u", "s", "send", "div"),
+		Gen.OneOf<string?>(null, null, "class=\"x\"", "href=\"north\" hint=\"Go north\""),
 		(tag, attributes) => (IMarkup)HtmlMarkup.Create(tag, attributes));
 
 	private static readonly Gen<MarkupSet> GenSet =
@@ -221,7 +221,7 @@ public void PadWithTruncation_NeverExceedsTheRequestedWidth()
 		};
 
 		Check.Sample(
-			Gen.Select(GenMarkupText, Gen.Int[0, 60], Gen.OneOfConst('.', '-', '*', ' ')),
+			Gen.Select(GenMarkupText, Gen.Int[0, 60], Gen.OneOf('.', '-', '*', ' ')),
 			property, seed: Seed, iter: 5000);
 	}