diff --git a/src/Compilers/CSharp/Portable/Emitter/EditAndContinue/CSharpDefinitionMap.cs b/src/Compilers/CSharp/Portable/Emitter/EditAndContinue/CSharpDefinitionMap.cs
index f1ecf6791e872114bcb9f1a13bd550ee016dee78..9b9acd524d897b95076077de23a5f74032309cd3 100644
--- a/src/Compilers/CSharp/Portable/Emitter/EditAndContinue/CSharpDefinitionMap.cs
+++ b/src/Compilers/CSharp/Portable/Emitter/EditAndContinue/CSharpDefinitionMap.cs
@@ -5,12 +5,10 @@
 using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Reflection.Metadata;
-using Microsoft.Cci;
 using Microsoft.CodeAnalysis.CodeGen;
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Symbols.Metadata.PE;
 using Microsoft.CodeAnalysis.Emit;
-using Microsoft.CodeAnalysis.Symbols;
 
 namespace Microsoft.CodeAnalysis.CSharp.Emit
 {
diff --git a/src/Compilers/Core/Portable/Emit/EditAndContinue/DefinitionMap.cs b/src/Compilers/Core/Portable/Emit/EditAndContinue/DefinitionMap.cs
index 70d78109d6dc53cf6229ff93d7e716bd1fbffc98..3866490e56397cc640ea03627340eec5a43f9ddc 100644
--- a/src/Compilers/Core/Portable/Emit/EditAndContinue/DefinitionMap.cs
+++ b/src/Compilers/Core/Portable/Emit/EditAndContinue/DefinitionMap.cs
@@ -8,7 +8,6 @@
 using System.Linq;
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
-using Microsoft.Cci;
 using Microsoft.CodeAnalysis.CodeGen;
 using Microsoft.CodeAnalysis.Symbols;
 using Roslyn.Utilities;
diff --git a/src/Compilers/Core/Portable/Emit/EditAndContinue/EncVariableSlotAllocator.cs b/src/Compilers/Core/Portable/Emit/EditAndContinue/EncVariableSlotAllocator.cs
index a6c92ceb4275956bc83bd5a9b3aef155982a5e04..94643adb8721a04cc5e5c92aca3f79398c227c20 100644
--- a/src/Compilers/Core/Portable/Emit/EditAndContinue/EncVariableSlotAllocator.cs
+++ b/src/Compilers/Core/Portable/Emit/EditAndContinue/EncVariableSlotAllocator.cs
@@ -11,7 +11,7 @@
 
 namespace Microsoft.CodeAnalysis.Emit
 {
-    internal class EncVariableSlotAllocator : VariableSlotAllocator
+    internal sealed class EncVariableSlotAllocator : VariableSlotAllocator
     {
         // symbols:
         private readonly SymbolMatcher _symbolMap;
diff --git a/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicDefinitionMap.vb b/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicDefinitionMap.vb
index 4e65122fe307dc1af6358560fafd48c79a80cc09..f0b6a98af2c0bd87aff2d0b0e91a25dfdc16074d 100644
--- a/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicDefinitionMap.vb
+++ b/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicDefinitionMap.vb
@@ -3,10 +3,8 @@
 Imports System.Collections.Immutable
 Imports System.Reflection.Metadata
 Imports System.Runtime.InteropServices
-Imports Microsoft.Cci
 Imports Microsoft.CodeAnalysis.CodeGen
 Imports Microsoft.CodeAnalysis.Emit
-Imports Microsoft.CodeAnalysis.Symbols
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols.Metadata.PE
 
diff --git a/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicEncVariableSlotAllocator.vb b/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicEncVariableSlotAllocator.vb
index a5c4b9b80ca1de03e423f46d66b49701d5983ad5..0a79845816b6b57e6d1cae1d23aa811a9eb99d52 100644
--- a/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicEncVariableSlotAllocator.vb
+++ b/src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/VisualBasicEncVariableSlotAllocator.vb
@@ -1,10 +1,6 @@
 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-Imports System.Collections.Immutable
-Imports Microsoft.Cci
-Imports Microsoft.CodeAnalysis.CodeGen
 Imports Microsoft.CodeAnalysis.Emit
-Imports Microsoft.CodeAnalysis.Symbols
 
 Namespace Microsoft.CodeAnalysis.VisualBasic.Emit
     Friend Class VisualBasicLambdaSyntaxHelper