diff --git a/tests/FixedPointNano.Tests/FixedPointNano.Tests.csproj b/tests/FixedPointNano.Tests/FixedPointNano.Tests.csproj
index b4f0081..5f90314 100644
--- a/tests/FixedPointNano.Tests/FixedPointNano.Tests.csproj
+++ b/tests/FixedPointNano.Tests/FixedPointNano.Tests.csproj
@@ -11,7 +11,6 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.0" />
-    <PackageReference Include="Moq" Version="4.20.72" />
     <PackageReference Include="NUnit" Version="4.3.2" />
     <PackageReference Include="NUnit.Analyzers" Version="4.7.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="5.0.0" />
diff --git a/tests/FixedPointNano.Tests/FixedPointNanoTests.cs b/tests/FixedPointNano.Tests/FixedPointNanoTests.cs
index 2795000..7ca3d00 100644
--- a/tests/FixedPointNano.Tests/FixedPointNanoTests.cs
+++ b/tests/FixedPointNano.Tests/FixedPointNanoTests.cs
@@ -1,7 +1,6 @@
 using System;
 using System.Globalization;
 using System.Numerics;
-using Moq;
 using Seerstone;
 
 namespace Seerstone.Tests;
@@ -231,18 +230,17 @@ public void ToStringAndTryFormatShouldUseProvidedFormatProvider()
         numberFormat.NumberDecimalSeparator = "_";
         numberFormat.NumberGroupSeparator = " ";
 
-        var provider = new Mock<IFormatProvider>(MockBehavior.Strict);
-        provider.Setup(x => x.GetFormat(typeof(NumberFormatInfo))).Returns(numberFormat);
+        var provider = new TrackingFormatProvider(numberFormat);
 
         var value = FixedPointNano.FromDecimal(1234.5m);
         Span<char> buffer = stackalloc char[32];
 
-        Assert.That(value.ToString(provider.Object), Is.EqualTo("1234_5"));
-        Assert.That(value.ToString("N2", provider.Object), Is.EqualTo("1 234_50"));
-        Assert.That(value.TryFormat(buffer, out var charsWritten, "F3", provider.Object), Is.True);
+        Assert.That(value.ToString(provider), Is.EqualTo("1234_5"));
+        Assert.That(value.ToString("N2", provider), Is.EqualTo("1 234_50"));
+        Assert.That(value.TryFormat(buffer, out var charsWritten, "F3", provider), Is.True);
         Assert.That(new string(buffer[..charsWritten]), Is.EqualTo("1234_500"));
 
-        provider.Verify(x => x.GetFormat(typeof(NumberFormatInfo)), Times.AtLeastOnce);
+        Assert.That(provider.GetFormatCallCount, Is.GreaterThan(0));
     }
 
     [Test]
@@ -432,6 +430,24 @@ public void Dispose()
         }
     }
 
+    private sealed class TrackingFormatProvider : IFormatProvider
+    {
+        private readonly NumberFormatInfo _numberFormat;
+
+        public int GetFormatCallCount { get; private set; }
+
+        public TrackingFormatProvider(NumberFormatInfo numberFormat)
+        {
+            _numberFormat = numberFormat;
+        }
+
+        public object? GetFormat(Type? formatType)
+        {
+            GetFormatCallCount++;
+            return formatType == typeof(NumberFormatInfo) ? _numberFormat : null;
+        }
+    }
+
     [Test]
     public void UnaryPlusOperatorShouldReturnSameValue()
     {