diff --git a/src/Hl7.Fhir.Base/Specification/Terminology/ValidateCodeParameters.cs b/src/Hl7.Fhir.Base/Specification/Terminology/ValidateCodeParameters.cs
index 34a59ade03..6534a4d727 100644
--- a/src/Hl7.Fhir.Base/Specification/Terminology/ValidateCodeParameters.cs
+++ b/src/Hl7.Fhir.Base/Specification/Terminology/ValidateCodeParameters.cs
@@ -164,9 +164,9 @@ public Parameters Build()
         {
             var result = new Parameters();
 
-            if (Url is { }) result.Add(_urlAttribute, Url); //Either Url, ValueSet or Context is allowed. So try Url first.
-            if (ValueSet is { } && Url is not { }) result.Add(_valueSetAttribute, ValueSet);
-            if (Context is { } && ValueSet is not { } && Url is not { }) result.Add(_contextAttribute, Context); //And then context as last resort.            
+            if (Url is { }) result.Add(_urlAttribute, Url);
+            if (ValueSet is { }) result.Add(_valueSetAttribute, ValueSet);
+            if (Context is { }) result.Add(_contextAttribute, Context);
             if (ValueSetVersion is { }) result.Add(_valueSetVersionAttribute, ValueSetVersion);
             if (Code is { }) result.Add(_codeAttribute, Code);
             if (System is { }) result.Add(_systemAttribute, System);
@@ -176,7 +176,7 @@ public Parameters Build()
             if (CodeableConcept is { }) result.Add(_codeableConceptAttribute, CodeableConcept);
             if (Date is { }) result.Add(_dateAttribute, Date);
             if (Abstract is { }) result.Add(_abstractAttribute, Abstract);
-            if (DisplayLanguage is { }) result.Add(_displayAttribute, DisplayLanguage);
+            if (DisplayLanguage is { }) result.Add(_displayLanguageAttribute, DisplayLanguage);
             if (InferSystem is { }) result.Add(_inferSystemAttribute, InferSystem);
             return result;
         }
diff --git a/src/Hl7.Fhir.Specification.Shared.Tests/Source/TerminologyTests.cs b/src/Hl7.Fhir.Specification.Shared.Tests/Source/TerminologyTests.cs
index f6d41e5958..327ceefc19 100644
--- a/src/Hl7.Fhir.Specification.Shared.Tests/Source/TerminologyTests.cs
+++ b/src/Hl7.Fhir.Specification.Shared.Tests/Source/TerminologyTests.cs
@@ -757,6 +757,52 @@ void expandAction(string url)
             }
         }
 
+        [Fact]
+        public void TestValidateCodeParametersCode()
+        {
+            var parameters = new ValidateCodeParameters()
+                .WithCode("bar", "http://foo.com", "1.0.4", "barDisplay", "nl-NL", "Patient.gender", true);
+
+            parameters.Code.Value.Should().Be("bar");
+            parameters.System.Value.Should().Be("http://foo.com");
+            parameters.SystemVersion.Value.Should().Be("1.0.4");
+            parameters.DisplayLanguage.Value.Should().Be("nl-NL");
+            parameters.Display.Value.Should().Be("barDisplay");
+            parameters.Context.Value.Should().Be("Patient.gender");
+            parameters.InferSystem.Value.Should().Be(true);
+
+            var paramResource = parameters.Build();
+
+            paramResource.Parameter.Should().HaveCount(7);
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "code" && ((Code)p.Value).Value == "bar");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "system" && ((FhirUri)p.Value).Value == "http://foo.com");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "systemVersion" && ((FhirString)p.Value).Value == "1.0.4");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "display" && ((FhirString)p.Value).Value == "barDisplay");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "displayLanguage" && ((Code)p.Value).Value == "nl-NL");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "context" && ((FhirUri)p.Value).Value == "Patient.gender");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "inferSystem" && ((FhirBoolean)p.Value).Value == true);
+        }
+
+        [Fact]
+        public void TestValidateCodeParametersValueSet()
+        {
+            var parameters = new ValidateCodeParameters()
+               .WithValueSet("http://foo.bar", "Patient.gender", new ValueSet(), "1.0.4");
+
+            parameters.Url.Value.Should().Be("http://foo.bar");
+            parameters.Context.Value.Should().Be("Patient.gender");
+            parameters.ValueSet.Should().NotBeNull();
+            parameters.ValueSetVersion.Value.Should().Be("1.0.4");
+
+            var paramResource = parameters.Build();
+
+            paramResource.Parameter.Should().HaveCount(4);
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "url" && ((FhirUri)p.Value).Value == "http://foo.bar");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "context" && ((FhirUri)p.Value).Value == "Patient.gender");
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "valueSet" && ((ValueSet)p.Resource) != null);
+            paramResource.Parameter.Should().ContainSingle(p => p.Name == "valueSetVersion" && ((FhirString)p.Value).Value == "1.0.4");
+        }
+
 
         #region helper functions
         private static Tasks.Task<Parameters> validateCodedValue(ITerminologyService service, string url = null, string context = null, string code = null,