diff --git a/src/WireMock.Net.FluentAssertions/Assertions/WireMockAssertions.cs b/src/WireMock.Net.FluentAssertions/Assertions/WireMockAssertions.cs
index 1b7e2fa5..5a08f32f 100644
--- a/src/WireMock.Net.FluentAssertions/Assertions/WireMockAssertions.cs
+++ b/src/WireMock.Net.FluentAssertions/Assertions/WireMockAssertions.cs
@@ -125,20 +125,27 @@ public partial class WireMockAssertions
     }
 
     [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithHeader(string expectedKey, string value, string because = "", params object[] becauseArgs)
-        => WithHeader(expectedKey, new[] { value }, because, becauseArgs);
-
-    [CustomAssertion]
-    public AndConstraint<WireMockAssertions> WithHeader(string expectedKey, string[] expectedValues, string because = "", params object[] becauseArgs)
+    public AndConstraint<WireMockAssertions> WitHeaderKey(string expectedKey, string because = "", params object[] becauseArgs)
     {
         using (new AssertionScope("headers from requests sent"))
         {
             _headers.Select(h => h.Key).Should().Contain(expectedKey, because, becauseArgs);
         }
 
+        return new AndConstraint<WireMockAssertions>(this);
+    }
+
+    [CustomAssertion]
+    public AndConstraint<WireMockAssertions> WithHeader(string expectedKey, string value, string because = "", params object[] becauseArgs)
+        => WithHeader(expectedKey, new[] { value }, because, becauseArgs);
+
+    [CustomAssertion]
+    public AndConstraint<WireMockAssertions> WithHeader(string expectedKey, string[] expectedValues, string because = "", params object[] becauseArgs)
+    {
         using (new AssertionScope($"header \"{expectedKey}\" from requests sent with value(s)"))
         {
-            var matchingHeaderValues = _headers.Where(h => h.Key == expectedKey).SelectMany(h => h.Value.ToArray()).ToArray();
+            var matchingHeaderValues = _headers.Where(h => h.Key == expectedKey).SelectMany(h => h.Value.ToArray())
+                .ToArray();
 
             if (expectedValues.Length == 1)
             {
@@ -157,6 +164,45 @@ public partial class WireMockAssertions
         return new AndConstraint<WireMockAssertions>(this);
     }
 
+    [CustomAssertion]
+    public AndConstraint<WireMockAssertions> WithoutHeaderKey(string unexpectedKey, string because = "", params object[] becauseArgs)
+    {
+        using (new AssertionScope("headers from requests sent"))
+        {
+            _headers.Select(h => h.Key).Should().NotContain(unexpectedKey, because, becauseArgs);
+        }
+
+        return new AndConstraint<WireMockAssertions>(this);
+    }
+
+    [CustomAssertion]
+    public AndConstraint<WireMockAssertions> WithoutHeader(string unexpectedKey, string value, string because = "", params object[] becauseArgs)
+        => WithoutHeader(unexpectedKey, new[] { value }, because, becauseArgs);
+
+    [CustomAssertion]
+    public AndConstraint<WireMockAssertions> WithoutHeader(string unexpectedKey, string[] expectedValues, string because = "", params object[] becauseArgs)
+    {
+        using (new AssertionScope($"header \"{unexpectedKey}\" from requests sent with value(s)"))
+        {
+            var matchingHeaderValues = _headers.Where(h => h.Key == unexpectedKey).SelectMany(h => h.Value.ToArray()).ToArray();
+
+            if (expectedValues.Length == 1)
+            {
+                matchingHeaderValues.Should().NotContain(expectedValues.First(), because, becauseArgs);
+            }
+            else
+            {
+                var trimmedHeaderValues = string.Join(",", matchingHeaderValues.Select(x => x)).Split(',').Select(x => x.Trim()).ToList();
+                foreach (var expectedValue in expectedValues)
+                {
+                    trimmedHeaderValues.Should().NotContain(expectedValue, because, becauseArgs);
+                }
+            }
+        }
+
+        return new AndConstraint<WireMockAssertions>(this);
+    }
+
     private (Func<IReadOnlyList<IRequestMessage>, IReadOnlyList<IRequestMessage>> Filter, Func<IReadOnlyList<IRequestMessage>, bool> Condition) BuildFilterAndCondition(Func<IRequestMessage, bool> predicate)
     {
         Func<IReadOnlyList<IRequestMessage>, IReadOnlyList<IRequestMessage>> filter = requests => requests.Where(predicate).ToList();
diff --git a/test/WireMock.Net.Tests/FluentAssertions/WireMockAssertionsTests.cs b/test/WireMock.Net.Tests/FluentAssertions/WireMockAssertionsTests.cs
index 49605536..c16fa4b9 100644
--- a/test/WireMock.Net.Tests/FluentAssertions/WireMockAssertionsTests.cs
+++ b/test/WireMock.Net.Tests/FluentAssertions/WireMockAssertionsTests.cs
@@ -130,6 +130,17 @@ public class WireMockAssertionsTests : IDisposable
         _httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer a");
         await _httpClient.GetAsync("").ConfigureAwait(false);
 
+        _server.Should()
+            .HaveReceivedACall()
+            .WitHeaderKey("Authorization");
+    }
+
+    [Fact]
+    public async Task HaveReceivedACall_WithHeader_WhenACallWasMadeWithExpectedHeaderWithValue_Should_BeOK()
+    {
+        _httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer a");
+        await _httpClient.GetAsync("").ConfigureAwait(false);
+
         _server.Should()
             .HaveReceivedACall()
             .WithHeader("Authorization", "Bearer a");
@@ -163,7 +174,7 @@ public class WireMockAssertionsTests : IDisposable
 
         act.Should().Throw<Exception>()
             .And.Message.Should()
-            .Contain("to contain \"Authorization\".");
+            .Contain("\"Authorization\"");
     }
 
     [Fact]
@@ -240,8 +251,13 @@ public class WireMockAssertionsTests : IDisposable
         });
 
         // Assert
-        server.Should().HaveReceivedACall().WithHeader("Authorization", "Bearer invalidToken");
-        server.Should().HaveReceivedACall().WithHeader("Authorization", "Bearer validToken");
+        server.Should()
+            .HaveReceivedACall()
+            .WithHeader("Authorization", "Bearer invalidToken").And.WithoutHeader("x", "y").And.WithoutHeaderKey("a");
+
+        server.Should().
+            HaveReceivedACall()
+            .WithHeader("Authorization", "Bearer validToken").And.WithoutHeader("Authorization", "y");
     }
 
     [Fact]