diff --git a/src/Workspaces/CSharp/Portable/Execution/CSharpOptionsSerializationService.cs b/src/Workspaces/CSharp/Portable/Execution/CSharpOptionsSerializationService.cs
index b92f5f775328892a922db490ed6ae2c2e5f6e212..41c3d8d9c1e7783f77bbda6586556ddc067eee21 100644
--- a/src/Workspaces/CSharp/Portable/Execution/CSharpOptionsSerializationService.cs
+++ b/src/Workspaces/CSharp/Portable/Execution/CSharpOptionsSerializationService.cs
@@ -1,7 +1,5 @@
 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Composition;
 using System.Linq;
 using System.Threading;
@@ -23,6 +21,7 @@ public override void WriteTo(CompilationOptions options, ObjectWriter writer, Ca
             var csharpOptions = (CSharpCompilationOptions)options;
             writer.WriteValue(csharpOptions.Usings.ToArray());
             writer.WriteBoolean(csharpOptions.AllowUnsafe);
+            writer.WriteByte((byte)csharpOptions.NullableContextOptions);
         }
 
         public override void WriteTo(ParseOptions options, ObjectWriter writer, CancellationToken cancellationToken)
@@ -81,16 +80,19 @@ public override CompilationOptions ReadCompilationOptionsFrom(ObjectReader reade
                 out var outputKind, out var reportSuppressedDiagnostics, out var moduleName, out var mainTypeName, out var scriptClassName,
                 out var optimizationLevel, out var checkOverflow, out var cryptoKeyContainer, out var cryptoKeyFile, out var cryptoPublicKey,
                 out var delaySign, out var platform, out var generalDiagnosticOption, out var warningLevel, out var specificDiagnosticOptions,
-                out var concurrentBuild, out var deterministic, out var publicSign, out var xmlReferenceResolver, out var sourceReferenceResolver,
-                out var metadataReferenceResolver, out var assemblyIdentityComparer, out var strongNameProvider, cancellationToken);
+                out var concurrentBuild, out var deterministic, out var publicSign, out var metadataImportOptions,
+                out var xmlReferenceResolver, out var sourceReferenceResolver, out var metadataReferenceResolver, out var assemblyIdentityComparer,
+                out var strongNameProvider, cancellationToken);
 
             var usings = reader.ReadArray<string>();
             var allowUnsafe = reader.ReadBoolean();
+            var nullableContextOptions = (NullableContextOptions)reader.ReadByte();
 
             return new CSharpCompilationOptions(
                 outputKind, reportSuppressedDiagnostics, moduleName, mainTypeName, scriptClassName, usings, optimizationLevel, checkOverflow, allowUnsafe,
                 cryptoKeyContainer, cryptoKeyFile, cryptoPublicKey, delaySign, platform, generalDiagnosticOption, warningLevel, specificDiagnosticOptions, concurrentBuild,
-                deterministic, xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver, assemblyIdentityComparer, strongNameProvider, publicSign);
+                deterministic, xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver, assemblyIdentityComparer, strongNameProvider, publicSign,
+                metadataImportOptions, nullableContextOptions);
         }
 
         public override ParseOptions ReadParseOptionsFrom(ObjectReader reader, CancellationToken cancellationToken)
diff --git a/src/Workspaces/Core/Portable/Execution/AbstractOptionsSerializationService.cs b/src/Workspaces/Core/Portable/Execution/AbstractOptionsSerializationService.cs
index 8f12a88b15fabac94a75cf0ca3e8c2162c0933bb..22b8b1daa7cbcd4a903bb2383d5e18e6ec37f507 100644
--- a/src/Workspaces/Core/Portable/Execution/AbstractOptionsSerializationService.cs
+++ b/src/Workspaces/Core/Portable/Execution/AbstractOptionsSerializationService.cs
@@ -65,6 +65,8 @@ protected void WriteCompilationOptionsTo(CompilationOptions options, ObjectWrite
             writer.WriteBoolean(options.Deterministic);
             writer.WriteBoolean(options.PublicSign);
 
+            writer.WriteByte((byte)options.MetadataImportOptions);
+
             // REVIEW: What should I do with these. we probably need to implement either out own one
             //         or somehow share these as service....
             //
@@ -95,6 +97,7 @@ protected void WriteCompilationOptionsTo(CompilationOptions options, ObjectWrite
             out bool concurrentBuild,
             out bool deterministic,
             out bool publicSign,
+            out MetadataImportOptions metadataImportOptions,
             out XmlReferenceResolver xmlReferenceResolver,
             out SourceReferenceResolver sourceReferenceResolver,
             out MetadataReferenceResolver metadataReferenceResolver,
@@ -152,6 +155,8 @@ protected void WriteCompilationOptionsTo(CompilationOptions options, ObjectWrite
             deterministic = reader.ReadBoolean();
             publicSign = reader.ReadBoolean();
 
+            metadataImportOptions = (MetadataImportOptions)reader.ReadByte();
+
             // REVIEW: What should I do with these. are these service required when compilation is built ourselves, not through
             //         compiler.
             xmlReferenceResolver = XmlFileResolver.Default;
diff --git a/src/Workspaces/CoreTest/Execution/SnapshotSerializationTests.cs b/src/Workspaces/CoreTest/Execution/SnapshotSerializationTests.cs
index a62492968a71312918ad513b8c4ad8453fc036ee..8086e3207083aff04348172b55964ea7fbccf657 100644
--- a/src/Workspaces/CoreTest/Execution/SnapshotSerializationTests.cs
+++ b/src/Workspaces/CoreTest/Execution/SnapshotSerializationTests.cs
@@ -609,6 +609,43 @@ public void TestEncodingSerialization()
             }
         }
 
+        [Fact]
+        public void TestCompilationOptions_NullableAndImport()
+        {
+            var csharpOptions = CSharp.CSharpCompilation.Create("dummy").Options.WithNullableContextOptions(CSharp.NullableContextOptions.SafeOnly).WithMetadataImportOptions(MetadataImportOptions.All);
+            var vbOptions = VisualBasic.VisualBasicCompilation.Create("dummy").Options.WithMetadataImportOptions(MetadataImportOptions.Internal);
+
+            var hostServices = MefHostServices.Create(MefHostServices.DefaultAssemblies);
+
+            var workspace = new AdhocWorkspace(hostServices);
+            var serializer = workspace.Services.GetService<ISerializerService>();
+
+            VerifyOptions(csharpOptions);
+            VerifyOptions(vbOptions);
+
+            void VerifyOptions(CompilationOptions originalOptions)
+            {
+                using (var stream = SerializableBytes.CreateWritableStream())
+                {
+                    using (var objectWriter = new ObjectWriter(stream))
+                    {
+                        serializer.Serialize(originalOptions, objectWriter, CancellationToken.None);
+                    }
+
+                    stream.Position = 0;
+                    using (var objectReader = ObjectReader.TryGetReader(stream))
+                    {
+                        var recoveredOptions = serializer.Deserialize<CompilationOptions>(originalOptions.GetWellKnownSynchronizationKind(), objectReader, CancellationToken.None);
+
+                        var original = serializer.CreateChecksum(originalOptions, CancellationToken.None);
+                        var recovered = serializer.CreateChecksum(recoveredOptions, CancellationToken.None);
+
+                        Assert.Equal(original, recovered);
+                    }
+                }
+            }
+        }
+
         private async Task<string> GetXmlDocumentAsync(HostServices services)
         {
             using (var tempRoot = new TempRoot())
diff --git a/src/Workspaces/VisualBasic/Portable/Execution/VisualBasicOptionsSerializationService.vb b/src/Workspaces/VisualBasic/Portable/Execution/VisualBasicOptionsSerializationService.vb
index 9715232b9bea57d476d6170cb7b62f0f9f3081d9..33de6d633ca9695a8455d1637a6ad31a3883ee90 100644
--- a/src/Workspaces/VisualBasic/Portable/Execution/VisualBasicOptionsSerializationService.vb
+++ b/src/Workspaces/VisualBasic/Portable/Execution/VisualBasicOptionsSerializationService.vb
@@ -72,6 +72,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Execution
             Dim concurrentBuild As Boolean
             Dim deterministic As Boolean
             Dim publicSign As Boolean
+            Dim metadataImportOptions As MetadataImportOptions = Nothing
             Dim xmlReferenceResolver As XmlReferenceResolver = Nothing
             Dim sourceReferenceResolver As SourceReferenceResolver = Nothing
             Dim metadataReferenceResolver As MetadataReferenceResolver = Nothing
@@ -81,8 +82,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Execution
             ReadCompilationOptionsFrom(reader, outputKind, reportSuppressedDiagnostics, moduleName, mainTypeName, scriptClassName,
                 optimizationLevel, checkOverflow, cryptoKeyContainer, cryptoKeyFile, cryptoPublicKey, delaySign,
                 platform, generalDiagnosticOption, warningLevel, specificDiagnosticOptions, concurrentBuild, deterministic,
-                publicSign, xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver, assemblyIdentityComparer, strongNameProvider,
-                cancellationToken)
+                publicSign, metadataImportOptions, xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver,
+                assemblyIdentityComparer, strongNameProvider, cancellationToken)
 
             Dim globalImports = GlobalImport.Parse(reader.ReadArray(Of String)())
             Dim rootNamespace = reader.ReadString()
@@ -102,7 +103,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Execution
                                                      cryptoKeyContainer, cryptoKeyFile, cryptoPublicKey, delaySign,
                                                      platform, generalDiagnosticOption, specificDiagnosticOptions, concurrentBuild, deterministic,
                                                      xmlReferenceResolver, sourceReferenceResolver, metadataReferenceResolver, assemblyIdentityComparer, strongNameProvider,
-                                                     publicSign, reportSuppressedDiagnostics)
+                                                     publicSign, reportSuppressedDiagnostics, metadataImportOptions)
         End Function
 
         Public Overrides Function ReadParseOptionsFrom(reader As ObjectReader, cancellationToken As CancellationToken) As ParseOptions