diff --git a/Src/Compilers/CSharp/Portable/Compilation/CSharpCompilation.cs b/Src/Compilers/CSharp/Portable/Compilation/CSharpCompilation.cs
index 5b7fb8ddf0f421fb33ce9a35892c6287f2c1d808..8085a9c1ee0e93db5dab5316123c761ed3135ffa 100644
--- a/Src/Compilers/CSharp/Portable/Compilation/CSharpCompilation.cs
+++ b/Src/Compilers/CSharp/Portable/Compilation/CSharpCompilation.cs
@@ -2348,6 +2348,7 @@ internal override FunctionId EmitFunctionId
             // testData is only passed when running tests.
             if (testData != null)
             {
+                testData.Compilation = this;
                 moduleBeingBuilt.SetMethodTestData(testData.Methods);
                 testData.Module = moduleBeingBuilt;
             }
diff --git a/Src/Compilers/CSharp/Portable/Emitter/EditAndContinue/EmitHelpers.cs b/Src/Compilers/CSharp/Portable/Emitter/EditAndContinue/EmitHelpers.cs
index 767bb55a87a054bb2cf2b57dfd4d8afe285d4990..c4858050a41fcb57ae3ca8554200f8283404a5ad 100644
--- a/Src/Compilers/CSharp/Portable/Emitter/EditAndContinue/EmitHelpers.cs
+++ b/Src/Compilers/CSharp/Portable/Emitter/EditAndContinue/EmitHelpers.cs
@@ -54,6 +54,7 @@ internal static class EmitHelpers
 
             if (testData != null)
             {
+                testData.Compilation = compilation;
                 moduleBeingBuilt.SetMethodTestData(testData.Methods);
                 testData.Module = moduleBeingBuilt;
             }
diff --git a/Src/Compilers/Core/Portable/CodeGen/CompilationTestData.cs b/Src/Compilers/Core/Portable/CodeGen/CompilationTestData.cs
index 2495c9857fc0f1d17ec26ffe1d0d49bb8e0febc9..c9a27d06cae626d8de4bb57c1663f8d0867392fb 100644
--- a/Src/Compilers/Core/Portable/CodeGen/CompilationTestData.cs
+++ b/Src/Compilers/Core/Portable/CodeGen/CompilationTestData.cs
@@ -19,6 +19,10 @@ public MethodData(ILBuilder ilBuilder, IMethodSymbol method)
             }
         }
 
+        // ILBuilder requires that Symbols still be alive when visualizing tokens from the IL stream.
+        // We'll hold on to a reference here.
+        public Compilation Compilation;
+
         // The map is used for storing a list of methods and their associated IL.
         // The key is a formatted qualified method name, e.g. Namespace.Class<T>.m<S>
         public readonly ConcurrentDictionary<string, MethodData> Methods = new ConcurrentDictionary<string, MethodData>();
@@ -27,5 +31,13 @@ public MethodData(ILBuilder ilBuilder, IMethodSymbol method)
         public Cci.IModule Module;
 
         public Func<object> SymWriterFactory;
+
+        public void Reset()
+        {
+            this.Compilation = null;
+            this.Methods.Clear();
+            this.Module = null;
+            this.SymWriterFactory = null;
+        }
     }
 }
diff --git a/Src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb b/Src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb
index 93077fc22340dbdd6ea04139c0c730184b09e8a0..25f8d762e604a136961e626bcd3a5c9c8c07dd80 100644
--- a/Src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb
+++ b/Src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb
@@ -2174,6 +2174,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End If
 
             If testData IsNot Nothing Then
+                testData.Compilation = Me
                 moduleBeingBuilt.SetMethodTestData(testData.Methods)
                 testData.Module = moduleBeingBuilt
             End If
diff --git a/Src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/EmitHelpers.vb b/Src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/EmitHelpers.vb
index acca17e2957c6bccc8fae6ffade6d5715ec239be..ff1920aa27f4e074b6dbceef221b1c1464dddb22 100644
--- a/Src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/EmitHelpers.vb
+++ b/Src/Compilers/VisualBasic/Portable/Emit/EditAndContinue/EmitHelpers.vb
@@ -46,6 +46,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Emit
                     edits:=edits)
 
             If testData IsNot Nothing Then
+                testData.Compilation = compilation
                 moduleBeingBuilt.SetMethodTestData(testData.Methods)
                 testData.Module = moduleBeingBuilt
             End If
diff --git a/Src/Test/Utilities/HostedRuntimeEnvironment.cs b/Src/Test/Utilities/HostedRuntimeEnvironment.cs
index aacfcd99a473f54a6618fbe0ee2510743a92f4ec..ab05157a6bb869cc4b19ca274593c876b5525e43 100644
--- a/Src/Test/Utilities/HostedRuntimeEnvironment.cs
+++ b/Src/Test/Utilities/HostedRuntimeEnvironment.cs
@@ -220,7 +220,7 @@ public void Emit(Compilation mainCompilation, IEnumerable<ResourceDescription> m
             var diagnostics = DiagnosticBag.GetInstance();
             var dependencies = new List<ModuleData>();
 
-            testData.Methods.Clear();
+            testData.Reset();
 
             ImmutableArray<byte> mainImage, mainPdb;
             bool succeeded = EmitCompilation(mainCompilation, manifestResources, dependencies, diagnostics, testData, out mainImage, out mainPdb);
@@ -409,6 +409,7 @@ void IDisposable.Dispose()
 
         internal CompilationTestData GetCompilationTestData()
         {
+            Debug.Assert(testData.Compilation != null, "If CompilationTestData does not have a pointer to the compilation that initialized it, then AVs may result when attempting to access Symbols during IL visualization.");
             if (testData.Module == null)
             {
                 throw new InvalidOperationException("You must call Emit before calling GetCompilationTestData.");