diff --git a/src/Protocol/Models/BooleanOr.cs b/src/Protocol/Models/BooleanOr.cs
index b0a6c0c8f..129783625 100644
--- a/src/Protocol/Models/BooleanOr.cs
+++ b/src/Protocol/Models/BooleanOr.cs
@@ -1,6 +1,6 @@
 namespace OmniSharp.Extensions.LanguageServer.Protocol.Models
 {
-    public struct BooleanOr<T>
+    public class BooleanOr<T>
     {
         private T _value;
         private bool? _bool;
@@ -48,7 +48,7 @@ public object RawValue
 
         public static implicit operator BooleanOr<T>(T value)
         {
-            return new BooleanOr<T>(value);
+            return value != null ? new BooleanOr<T>(value) : null;
         }
 
         public static implicit operator BooleanOr<T>(bool value)
diff --git a/src/Protocol/Serialization/Converters/BooleanOrConverter.cs b/src/Protocol/Serialization/Converters/BooleanOrConverter.cs
index e579f08a6..590ae63fb 100644
--- a/src/Protocol/Serialization/Converters/BooleanOrConverter.cs
+++ b/src/Protocol/Serialization/Converters/BooleanOrConverter.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Reflection;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
@@ -29,7 +29,7 @@ private static void WriteJsonGeneric<T>(JsonWriter writer, BooleanOr<T> value, J
                 return;
             }
 
-            if (value.IsBool && value.Bool)
+            if (value.IsBool)
             {
                 new JValue(value.Bool).WriteTo(writer);
                 return;
@@ -57,11 +57,11 @@ private static BooleanOr<T> ReadJsonGeneric<T>(JsonReader reader, object existin
                 return new BooleanOr<T>(JObject.Load(reader).ToObject<T>(serializer));
             }
 
-            return new BooleanOr<T>();
+            return new BooleanOr<T>(default(T));
         }
 
         public override bool CanRead => true;
 
         public override bool CanConvert(Type objectType) => objectType.GetTypeInfo().IsGenericType && objectType.GetTypeInfo().GetGenericTypeDefinition() == typeof(BooleanOr<>);
     }
-}
\ No newline at end of file
+}
diff --git a/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests.cs b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests.cs
index 4998c557f..9ba80eb92 100644
--- a/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests.cs
+++ b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests.cs
@@ -5,6 +5,7 @@
 using Newtonsoft.Json.Linq;
 using OmniSharp.Extensions.LanguageServer.Protocol;
 using OmniSharp.Extensions.LanguageServer.Protocol.Client.Capabilities;
+using OmniSharp.Extensions.LanguageServer.Protocol.Models;
 using OmniSharp.Extensions.LanguageServer.Protocol.Serialization;
 using OmniSharp.Extensions.LanguageServer.Protocol.Server.Capabilities;
 using Xunit;
@@ -59,6 +60,10 @@ public void SimpleTest(string expected)
                     WillSaveWaitUntil = true
                 }),
                 WorkspaceSymbolProvider = true,
+                ColorProvider = true,
+                FoldingRangeProvider = true,
+                ImplementationProvider = true,
+                TypeDefinitionProvider = true
             };
             var result = Fixture.SerializeObject(model);
 
@@ -67,5 +72,20 @@ public void SimpleTest(string expected)
             var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<ServerCapabilities>(expected);
             deresult.Should().BeEquivalentTo(model);
         }
+
+        [Theory, JsonFixture]
+        public void Optional(string expected)
+        {
+            var model = new ServerCapabilities {
+                ColorProvider = (ColorOptions)null
+            };
+
+            var result = Fixture.SerializeObject(model);
+
+            result.Should().Be(expected);
+
+            var deresult = new Serializer(ClientVersion.Lsp3).DeserializeObject<ServerCapabilities>(expected);
+            deresult.Should().BeEquivalentTo(model);
+        }
     }
 }
diff --git a/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$Optional.json b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$Optional.json
new file mode 100644
index 000000000..35e551e8f
--- /dev/null
+++ b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$Optional.json
@@ -0,0 +1,11 @@
+{
+    "hoverProvider": false,
+    "definitionProvider": false,
+    "referencesProvider": false,
+    "documentHighlightProvider": false,
+    "documentSymbolProvider": false,
+    "workspaceSymbolProvider": false,
+    "documentFormattingProvider": false,
+    "documentRangeFormattingProvider": false,
+    "experimental": {}
+}
diff --git a/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$SimpleTest.json b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$SimpleTest.json
index 6382ada38..d20a13f2e 100644
--- a/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$SimpleTest.json
+++ b/test/Lsp.Tests/Capabilities/Server/ServerCapabilitiesTests_$SimpleTest.json
@@ -54,8 +54,8 @@
     "experimental": {
         "abc": "123"
     },
-    "typeDefinitionProvider": null,
-    "implementationProvider": null,
-    "colorProvider": null,
-    "foldingRangeProvider": null
+    "typeDefinitionProvider": true,
+    "implementationProvider": true,
+    "colorProvider": true,
+    "foldingRangeProvider": true
 }
diff --git a/test/Lsp.Tests/Models/InitializeResultTests_$SimpleTest.json b/test/Lsp.Tests/Models/InitializeResultTests_$SimpleTest.json
index 73bcc9a79..7f553ba93 100644
--- a/test/Lsp.Tests/Models/InitializeResultTests_$SimpleTest.json
+++ b/test/Lsp.Tests/Models/InitializeResultTests_$SimpleTest.json
@@ -54,10 +54,6 @@
         },
         "experimental": {
             "abc": "123"
-        },
-        "typeDefinitionProvider": null,
-        "implementationProvider": null,
-        "colorProvider": null,
-        "foldingRangeProvider": null
+        }
     }
 }