diff --git a/X10D.Tests/src/Text/CharTests.cs b/X10D.Tests/src/Text/CharTests.cs
index 5ac8840..cc6d941 100644
--- a/X10D.Tests/src/Text/CharTests.cs
+++ b/X10D.Tests/src/Text/CharTests.cs
@@ -51,6 +51,6 @@ internal class CharTests
     [Test]
     public void RepeatNegativeCountShouldThrow()
     {
-        Assert.Throws<ArgumentOutOfRangeException>(() => 'a'.Repeat(-1));
+        Assert.Throws<ArgumentOutOfRangeException>(() => _ = 'a'.Repeat(-1));
     }
 }