diff --git a/src/WireMock.Net/Matchers/JsonMatcher.cs b/src/WireMock.Net/Matchers/JsonMatcher.cs
index 29602318..6ff6bfce 100644
--- a/src/WireMock.Net/Matchers/JsonMatcher.cs
+++ b/src/WireMock.Net/Matchers/JsonMatcher.cs
@@ -53,7 +53,7 @@ public class JsonMatcher : IValueMatcher, IIgnoreCaseMatcher
     /// <param name="ignoreCase">Ignore the case from the PropertyName and PropertyValue (string only).</param>
     public JsonMatcher(MatchBehaviour matchBehaviour, object value, bool ignoreCase = false)
     {
-        Guard.NotNull(value, nameof(value));
+        Guard.NotNull(value);
 
         MatchBehaviour = matchBehaviour;
         IgnoreCase = ignoreCase;
diff --git a/src/WireMock.Net/Matchers/Request/RequestMessageParamMatcher.cs b/src/WireMock.Net/Matchers/Request/RequestMessageParamMatcher.cs
index 97070352..fcd9749c 100644
--- a/src/WireMock.Net/Matchers/Request/RequestMessageParamMatcher.cs
+++ b/src/WireMock.Net/Matchers/Request/RequestMessageParamMatcher.cs
@@ -85,11 +85,11 @@ public class RequestMessageParamMatcher : IRequestMatcher
     /// <inheritdoc />
     public double GetMatchingScore(IRequestMessage requestMessage, IRequestMatchResult requestMatchResult)
     {
-        var (score, exception) = GetMatchResult(requestMessage).Expand();
-        return requestMatchResult.AddScore(GetType(), score, exception);
+        var score = GetMatchScore(requestMessage);
+        return requestMatchResult.AddScore(GetType(), MatchBehaviourHelper.Convert(MatchBehaviour, score), null);
     }
 
-    private MatchResult GetMatchResult(IRequestMessage requestMessage)
+    private double GetMatchScore(IRequestMessage requestMessage)
     {
         if (Funcs != null)
         {
@@ -100,7 +100,7 @@ public class RequestMessageParamMatcher : IRequestMatcher
         if (valuesPresentInRequestMessage == null)
         {
             // Key is not present at all, just return Mismatch
-            return default;
+            return MatchScores.Mismatch;
         }
 
         if (Matchers != null && Matchers.Any())
@@ -115,10 +115,10 @@ public class RequestMessageParamMatcher : IRequestMatcher
             return MatchScores.Perfect;
         }
 
-        return default;
+        return MatchScores.Mismatch;
     }
 
-    private static MatchResult CalculateScore(IReadOnlyList<IStringMatcher> matchers, WireMockList<string> valuesPresentInRequestMessage)
+    private static double CalculateScore(IReadOnlyList<IStringMatcher> matchers, WireMockList<string> valuesPresentInRequestMessage)
     {
         var total = new List<double>();
 
diff --git a/test/WireMock.Net.Tests/WireMockServerTests.WithParam.cs b/test/WireMock.Net.Tests/WireMockServerTests.WithParam.cs
index 8f70eb65..7cb809c8 100644
--- a/test/WireMock.Net.Tests/WireMockServerTests.WithParam.cs
+++ b/test/WireMock.Net.Tests/WireMockServerTests.WithParam.cs
@@ -2,6 +2,7 @@ using System;
 using System.Net;
 using System.Threading.Tasks;
 using FluentAssertions;
+using WireMock.Matchers;
 using WireMock.RequestBuilders;
 using WireMock.ResponseBuilders;
 using WireMock.Server;
@@ -26,10 +27,10 @@ public partial class WireMockServerTests
         };
         var server = WireMockServer.Start(settings);
         server.Given(
-                Request.Create()
-                    .UsingGet()
-                    .WithPath("/foo")
-                    .WithParam("query", queryValue)
+            Request.Create()
+                .UsingGet()
+                .WithPath("/foo")
+                .WithParam("query", queryValue)
             )
             .RespondWith(
                 Response.Create().WithStatusCode(200)
@@ -52,10 +53,10 @@ public partial class WireMockServerTests
         var queryValue = "1,2,3";
         var server = WireMockServer.Start();
         server.Given(
-                Request.Create()
-                    .UsingGet()
-                    .WithPath("/foo")
-                    .WithParam("query", "1", "2", "3")
+            Request.Create()
+                .UsingGet()
+                .WithPath("/foo")
+                .WithParam("query", "1", "2", "3")
             )
             .RespondWith(
                 Response.Create().WithStatusCode(200)
@@ -70,4 +71,54 @@ public partial class WireMockServerTests
 
         server.Stop();
     }
+
+    [Fact]
+    public async Task WireMockServer_WithParam_RejectOnMatch_OnNonMatchingParam_ShouldReturnMappingOk()
+    {
+        // Arrange
+        var server = WireMockServer.Start();
+        server.Given(
+            Request.Create()
+                .WithPath("/v1/person/workers")
+                .WithParam("delta_from", MatchBehaviour.RejectOnMatch)
+                .UsingGet()
+            )
+            .RespondWith(
+                Response.Create()
+            );
+
+        // Act
+        var requestUri = new Uri($"http://localhost:{server.Port}/v1/person/workers?showsourcesystem=true&count=700&page=1&sections=personal%2Corganizations%2Cemployment");
+        var response = await server.CreateClient().GetAsync(requestUri).ConfigureAwait(false);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.OK);
+
+        server.Stop();
+    }
+
+    [Fact]
+    public async Task WireMockServer_WithParam_AcceptOnMatch_OnNonMatchingParam_ShouldReturnMappingOk()
+    {
+        // Arrange
+        var server = WireMockServer.Start();
+        server.Given(
+            Request.Create()
+                .WithPath("/v1/person/workers")
+                .WithParam("delta_from")
+                .UsingGet()
+            )
+            .RespondWith(
+                Response.Create()
+            );
+
+        // Act
+        var requestUri = new Uri($"http://localhost:{server.Port}/v1/person/workers?showsourcesystem=true&count=700&page=1&sections=personal%2Corganizations%2Cemployment");
+        var response = await server.CreateClient().GetAsync(requestUri).ConfigureAwait(false);
+
+        // Assert
+        response.StatusCode.Should().Be(HttpStatusCode.NotFound);
+
+        server.Stop();
+    }
 }
\ No newline at end of file