diff --git a/tests/Aspire.Dashboard.Tests/FormatHelpersTests.cs b/tests/Aspire.Dashboard.Tests/FormatHelpersTests.cs
index de7c1736b47..010fb7af17f 100644
--- a/tests/Aspire.Dashboard.Tests/FormatHelpersTests.cs
+++ b/tests/Aspire.Dashboard.Tests/FormatHelpersTests.cs
@@ -4,7 +4,6 @@
 using System.Globalization;
 using Aspire.Dashboard.Model;
 using Aspire.Dashboard.Utils;
-using Aspire.TestUtilities;
 using Microsoft.Extensions.Logging.Abstractions;
 using Xunit;
 
@@ -76,11 +75,11 @@ public void FormatDateTime_WithMilliseconds_FinnishCulture(string expected, Mill
     [InlineData("15/06/2009 1:45:30.1234567 pm", MillisecondsDisplay.Full, "2009-06-15T13:45:30.1234567Z")]
     [InlineData("15/06/2009 1:45:30 pm", MillisecondsDisplay.None, "2009-06-15T13:45:30.0000000Z")]
     [InlineData("15/06/2009 1:45:30 pm", MillisecondsDisplay.None, "2009-06-15T13:45:30.1234567Z")]
-    [ActiveIssue("https://github.com/dotnet/aspire/issues/9151", typeof(PlatformDetection), nameof(PlatformDetection.IsMacOS))]
     public void FormatDateTime_WithMilliseconds_NewZealandCulture(string expected, MillisecondsDisplay includeMilliseconds, string value)
     {
         var date = GetLocalDateTime(value);
-        Assert.Equal(expected, FormatHelpers.FormatDateTime(CreateTimeProvider(), date, includeMilliseconds, cultureInfo: CultureInfo.GetCultureInfo("en-NZ")), ignoreWhiteSpaceDifferences: true);
+        // macOS formats with uppercase AM/PM, so ignore case
+        Assert.Equal(expected, FormatHelpers.FormatDateTime(CreateTimeProvider(), date, includeMilliseconds, cultureInfo: CultureInfo.GetCultureInfo("en-NZ")), ignoreWhiteSpaceDifferences: true, ignoreCase: true);
     }
 
     private static DateTime GetLocalDateTime(string value)