diff --git a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.net40.fs b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.net40.fs
index 199aa0af64..16f23c386f 100644
--- a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.net40.fs
+++ b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.net40.fs
@@ -916,6 +916,7 @@ Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.String
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T LastGenerated
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T get_LastGenerated()
+Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void .ctor()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void Close()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace[] GetNestedNamespaces()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: System.String NamespaceName
@@ -2090,6 +2091,7 @@ Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.String ToString()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: TResult Invoke(T)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: V InvokeFast[V](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,V]], T, TResult)
+Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Void .ctor()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: W InvokeFast[V,W](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,W]]], T, TResult, V)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: X InvokeFast[V,W,X](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,X]]]], T, TResult, V, W)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Y InvokeFast[V,W,X,Y](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,Microsoft.FSharp.Core.FSharpFunc`2[X,Y]]]]], T, TResult, V, W, X)
@@ -2159,6 +2161,7 @@ Microsoft.FSharp.Core.FSharpTypeFunc: Int32 GetHashCode()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Object Specialize[T]()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.String ToString()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Type GetType()
+Microsoft.FSharp.Core.FSharpTypeFunc: Void .ctor()
 Microsoft.FSharp.Core.FuncConvert: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.FuncConvert: Int32 GetHashCode()
 Microsoft.FSharp.Core.FuncConvert: Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.Unit] ToFSharpFunc[T](System.Action`1[T])
@@ -2675,6 +2678,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Microsoft.F
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: TResult Invoke(T1, T2)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: FSharpFunc`4 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,TResult]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Int32 GetHashCode()
@@ -2682,6 +2686,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Microsof
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: TResult Invoke(T1, T2, T3)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: FSharpFunc`5 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,TResult]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Int32 GetHashCode()
@@ -2689,6 +2694,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Micro
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: TResult Invoke(T1, T2, T3, T4)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: FSharpFunc`6 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,Microsoft.FSharp.Core.FSharpFunc`2[T5,TResult]]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Int32 GetHashCode()
@@ -2696,6 +2702,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Mi
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: TResult Invoke(T1, T2, T3, T4, T5)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures: Int32 GetHashCode()
 Microsoft.FSharp.Core.OptimizedClosures: Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]
diff --git a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable259.fs b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable259.fs
index 4f7a5b95fb..2114a808c2 100644
--- a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable259.fs
+++ b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable259.fs
@@ -900,6 +900,7 @@ Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.String
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T LastGenerated
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T get_LastGenerated()
+Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void .ctor()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void Close()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace[] GetNestedNamespaces()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: System.String NamespaceName
@@ -2066,6 +2067,7 @@ Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.String ToString()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: TResult Invoke(T)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: V InvokeFast[V](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,V]], T, TResult)
+Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Void .ctor()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: W InvokeFast[V,W](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,W]]], T, TResult, V)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: X InvokeFast[V,W,X](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,X]]]], T, TResult, V, W)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Y InvokeFast[V,W,X,Y](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,Microsoft.FSharp.Core.FSharpFunc`2[X,Y]]]]], T, TResult, V, W, X)
@@ -2135,6 +2137,7 @@ Microsoft.FSharp.Core.FSharpTypeFunc: Int32 GetHashCode()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Object Specialize[T]()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.String ToString()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Type GetType()
+Microsoft.FSharp.Core.FSharpTypeFunc: Void .ctor()
 Microsoft.FSharp.Core.FuncConvert: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.FuncConvert: Int32 GetHashCode()
 Microsoft.FSharp.Core.FuncConvert: Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.Unit] ToFSharpFunc[T](System.Action`1[T])
@@ -2646,6 +2649,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Microsoft.F
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: TResult Invoke(T1, T2)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: FSharpFunc`4 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,TResult]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Int32 GetHashCode()
@@ -2653,6 +2657,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Microsof
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: TResult Invoke(T1, T2, T3)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: FSharpFunc`5 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,TResult]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Int32 GetHashCode()
@@ -2660,6 +2665,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Micro
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: TResult Invoke(T1, T2, T3, T4)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: FSharpFunc`6 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,Microsoft.FSharp.Core.FSharpFunc`2[T5,TResult]]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Int32 GetHashCode()
@@ -2667,6 +2673,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Mi
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: TResult Invoke(T1, T2, T3, T4, T5)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures: Int32 GetHashCode()
 Microsoft.FSharp.Core.OptimizedClosures: Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]
diff --git a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable47.fs b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable47.fs
index c441cddafb..aaa2e56293 100644
--- a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable47.fs
+++ b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable47.fs
@@ -897,6 +897,7 @@ Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.String
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T LastGenerated
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T get_LastGenerated()
+Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void .ctor()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void Close()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace[] GetNestedNamespaces()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: System.String NamespaceName
@@ -2063,6 +2064,7 @@ Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.String ToString()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: TResult Invoke(T)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: V InvokeFast[V](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,V]], T, TResult)
+Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Void .ctor()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: W InvokeFast[V,W](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,W]]], T, TResult, V)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: X InvokeFast[V,W,X](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,X]]]], T, TResult, V, W)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Y InvokeFast[V,W,X,Y](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,Microsoft.FSharp.Core.FSharpFunc`2[X,Y]]]]], T, TResult, V, W, X)
@@ -2132,6 +2134,7 @@ Microsoft.FSharp.Core.FSharpTypeFunc: Int32 GetHashCode()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Object Specialize[T]()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.String ToString()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Type GetType()
+Microsoft.FSharp.Core.FSharpTypeFunc: Void .ctor()
 Microsoft.FSharp.Core.FuncConvert: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.FuncConvert: Int32 GetHashCode()
 Microsoft.FSharp.Core.FuncConvert: Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.Unit] ToFSharpFunc[T](System.Action`1[T])
@@ -2647,6 +2650,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Microsoft.F
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: TResult Invoke(T1, T2)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: FSharpFunc`4 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,TResult]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Int32 GetHashCode()
@@ -2654,6 +2658,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Microsof
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: TResult Invoke(T1, T2, T3)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: FSharpFunc`5 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,TResult]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Int32 GetHashCode()
@@ -2661,6 +2666,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Micro
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: TResult Invoke(T1, T2, T3, T4)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: FSharpFunc`6 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,Microsoft.FSharp.Core.FSharpFunc`2[T5,TResult]]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Int32 GetHashCode()
@@ -2668,6 +2674,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Mi
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: TResult Invoke(T1, T2, T3, T4, T5)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures: Int32 GetHashCode()
 Microsoft.FSharp.Core.OptimizedClosures: Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]
diff --git a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable7.fs b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable7.fs
index 18a4469ded..a31efab40e 100644
--- a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable7.fs
+++ b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable7.fs
@@ -913,6 +913,7 @@ Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.String
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T LastGenerated
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T get_LastGenerated()
+Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void .ctor()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void Close()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace[] GetNestedNamespaces()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: System.String NamespaceName
@@ -2079,6 +2080,7 @@ Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.String ToString()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: TResult Invoke(T)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: V InvokeFast[V](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,V]], T, TResult)
+Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Void .ctor()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: W InvokeFast[V,W](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,W]]], T, TResult, V)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: X InvokeFast[V,W,X](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,X]]]], T, TResult, V, W)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Y InvokeFast[V,W,X,Y](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,Microsoft.FSharp.Core.FSharpFunc`2[X,Y]]]]], T, TResult, V, W, X)
@@ -2148,6 +2150,7 @@ Microsoft.FSharp.Core.FSharpTypeFunc: Int32 GetHashCode()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Object Specialize[T]()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.String ToString()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Type GetType()
+Microsoft.FSharp.Core.FSharpTypeFunc: Void .ctor()
 Microsoft.FSharp.Core.FuncConvert: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.FuncConvert: Int32 GetHashCode()
 Microsoft.FSharp.Core.FuncConvert: Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.Unit] ToFSharpFunc[T](System.Action`1[T])
@@ -2659,6 +2662,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Microsoft.F
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: TResult Invoke(T1, T2)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: FSharpFunc`4 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,TResult]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Int32 GetHashCode()
@@ -2666,6 +2670,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Microsof
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: TResult Invoke(T1, T2, T3)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: FSharpFunc`5 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,TResult]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Int32 GetHashCode()
@@ -2673,6 +2678,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Micro
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: TResult Invoke(T1, T2, T3, T4)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: FSharpFunc`6 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,Microsoft.FSharp.Core.FSharpFunc`2[T5,TResult]]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Int32 GetHashCode()
@@ -2680,6 +2686,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Mi
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: TResult Invoke(T1, T2, T3, T4, T5)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures: Int32 GetHashCode()
 Microsoft.FSharp.Core.OptimizedClosures: Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]
diff --git a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable78.fs b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable78.fs
index 9cbf2f09d2..aec1daf060 100644
--- a/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable78.fs
+++ b/src/fsharp/FSharp.Core.Unittests/SurfaceArea.portable78.fs
@@ -900,6 +900,7 @@ Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.String
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: System.Type GetType()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T LastGenerated
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: T get_LastGenerated()
+Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void .ctor()
 Microsoft.FSharp.Core.CompilerServices.GeneratedSequenceBase`1[T]: Void Close()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace[] GetNestedNamespaces()
 Microsoft.FSharp.Core.CompilerServices.IProvidedNamespace: System.String NamespaceName
@@ -2066,6 +2067,7 @@ Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.String ToString()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: TResult Invoke(T)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: V InvokeFast[V](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,V]], T, TResult)
+Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Void .ctor()
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: W InvokeFast[V,W](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,W]]], T, TResult, V)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: X InvokeFast[V,W,X](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,X]]]], T, TResult, V, W)
 Microsoft.FSharp.Core.FSharpFunc`2[T,TResult]: Y InvokeFast[V,W,X,Y](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpFunc`2[TResult,Microsoft.FSharp.Core.FSharpFunc`2[V,Microsoft.FSharp.Core.FSharpFunc`2[W,Microsoft.FSharp.Core.FSharpFunc`2[X,Y]]]]], T, TResult, V, W, X)
@@ -2135,6 +2137,7 @@ Microsoft.FSharp.Core.FSharpTypeFunc: Int32 GetHashCode()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Object Specialize[T]()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.String ToString()
 Microsoft.FSharp.Core.FSharpTypeFunc: System.Type GetType()
+Microsoft.FSharp.Core.FSharpTypeFunc: Void .ctor()
 Microsoft.FSharp.Core.FuncConvert: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.FuncConvert: Int32 GetHashCode()
 Microsoft.FSharp.Core.FuncConvert: Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.Unit] ToFSharpFunc[T](System.Action`1[T])
@@ -2646,6 +2649,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Microsoft.F
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: TResult Invoke(T1, T2)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: FSharpFunc`4 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,TResult]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Int32 GetHashCode()
@@ -2653,6 +2657,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Microsof
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: TResult Invoke(T1, T2, T3)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`4[T1,T2,T3,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: FSharpFunc`5 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,TResult]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Int32 GetHashCode()
@@ -2660,6 +2665,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Micro
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: TResult Invoke(T1, T2, T3, T4)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`5[T1,T2,T3,T4,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: FSharpFunc`6 Adapt(Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.FSharpFunc`2[T3,Microsoft.FSharp.Core.FSharpFunc`2[T4,Microsoft.FSharp.Core.FSharpFunc`2[T5,TResult]]]]])
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Int32 GetHashCode()
@@ -2667,6 +2673,7 @@ Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Mi
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.String ToString()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: System.Type GetType()
 Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: TResult Invoke(T1, T2, T3, T4, T5)
+Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`6[T1,T2,T3,T4,T5,TResult]: Void .ctor()
 Microsoft.FSharp.Core.OptimizedClosures: Boolean Equals(System.Object)
 Microsoft.FSharp.Core.OptimizedClosures: Int32 GetHashCode()
 Microsoft.FSharp.Core.OptimizedClosures: Microsoft.FSharp.Core.OptimizedClosures+FSharpFunc`3[T1,T2,TResult]
diff --git a/src/fsharp/ilxgen.fs b/src/fsharp/ilxgen.fs
index 1cc855354b..a1788f62b5 100644
--- a/src/fsharp/ilxgen.fs
+++ b/src/fsharp/ilxgen.fs
@@ -5291,14 +5291,6 @@ and GenMethodForBinding
        let ilMethTypars = ilTypars |> List.drop mspec.EnclosingType.GenericArgs.Length
        if memberInfo.MemberFlags.MemberKind = MemberKind.Constructor then 
            assert (isNil ilMethTypars)
-
-           // Constructors in abstract classes become protected
-           let access = 
-               if HasFSharpAttribute cenv.g cenv.g.attrib_AbstractClassAttribute v.MemberApparentParent.Attribs then 
-                   ILMemberAccess.Family
-               else 
-                   access
-
            let mdef = mkILCtor (access,ilParams,ilMethodBody) 
            let mdef = { mdef with CustomAttrs= mkILCustomAttrs (ilAttrsThatGoOnPrimaryItem @ sourceNameAttribs @ ilAttrsCompilerGenerated) }; 
            EmitTheMethodDef mdef
diff --git a/src/ilx/cu_erase.fs b/src/ilx/cu_erase.fs
index c4d9a32975..1a2be51f2c 100644
--- a/src/ilx/cu_erase.fs
+++ b/src/ilx/cu_erase.fs
@@ -1037,13 +1037,6 @@ let rec convClassUnionDef cenv enc td cud =
     // The class can be abstract if each alternative is represented by a derived type
     let isAbstract = (altTypeDefs.Length = cud.cudAlternatives.Length)        
 
-    // If the class is abstract make the constructor used for the subclasses protected
-    let ctorMeths = 
-        if isAbstract then 
-            ctorMeths |> List.map (fun mdef -> {mdef with Access=ILMemberAccess.Assembly })
-        else   
-            ctorMeths
-
     let existingMeths = 
         td.Methods.AsList 
             // Filter out the F#-compiler supplied implementation of the get_Empty method. This is because we will replace
diff --git a/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.bsl b/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.bsl
index 54a89679a3..1f8e155f62 100644
--- a/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.bsl
+++ b/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.bsl
@@ -68,7 +68,7 @@
     {
     } // end of method C::A2
 
-    .method family specialname rtspecialname 
+    .method public specialname rtspecialname 
             instance void  .ctor() cil managed
     {
       // Code size       10 (0xa)
diff --git a/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.netfx4.bsl b/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.netfx4.bsl
index f54cf2ec81..a38431b8f6 100644
--- a/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.netfx4.bsl
+++ b/tests/fsharpqa/Source/CodeGen/EmittedIL/CompiledNameAttribute/CompiledNameAttribute04.il.netfx4.bsl
@@ -68,7 +68,7 @@
     {
     } // end of method C::A2
 
-    .method family specialname rtspecialname 
+    .method public specialname rtspecialname 
             instance void  .ctor() cil managed
     {
       // Code size       10 (0xa)
diff --git a/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.fs b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.fs
new file mode 100644
index 0000000000..5210295c8e
--- /dev/null
+++ b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.fs
@@ -0,0 +1,8 @@
+// regression test for https://github.com/Microsoft/visualfsharp/issues/420
+
+[<AbstractClass>]
+type X public (i : int) =
+    internal new() = X(1)
+    private new(f : float32) = X(1)
+
+exit 0
\ No newline at end of file
diff --git a/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.il.bsl b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.il.bsl
new file mode 100644
index 0000000000..3ecf71cd3a
--- /dev/null
+++ b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/AbstractClass.il.bsl
@@ -0,0 +1,129 @@
+
+//  Microsoft (R) .NET Framework IL Disassembler.  Version 4.0.30319.1
+//  Copyright (c) Microsoft Corporation.  All rights reserved.
+
+
+
+// Metadata version: v4.0.30319
+.assembly extern mscorlib
+{
+  .publickeytoken = (B7 7A 5C 56 19 34 E0 89 )                         // .z\V.4..
+  .ver 4:0:0:0
+}
+.assembly extern FSharp.Core
+{
+  .publickeytoken = (B0 3F 5F 7F 11 D5 0A 3A )                         // .?_....:
+  .ver 4:4:0:9055
+}
+.assembly AbstractClass
+{
+  .custom instance void [FSharp.Core]Microsoft.FSharp.Core.FSharpInterfaceDataVersionAttribute::.ctor(int32,
+                                                                                                      int32,
+                                                                                                      int32) = ( 01 00 02 00 00 00 00 00 00 00 00 00 00 00 00 00 ) 
+
+  // 
+  //  .custom instance void [mscorlib]System.Diagnostics.DebuggableAttribute::.ctor(valuetype [mscorlib]System.Diagnostics.DebuggableAttribute/DebuggingModes) = ( 01 00 01 01 00 00 00 00 ) 
+
+  .hash algorithm 0x00008004
+  .ver 0:0:0:0
+}
+.mresource public FSharpSignatureData.AbstractClass
+{
+  // Offset: 0x00000000 Length: 0x00000308
+}
+.mresource public FSharpOptimizationData.AbstractClass
+{
+  // Offset: 0x00000310 Length: 0x000000B1
+}
+.module AbstractClass.exe
+// MVID: {554AAD5A-333C-8BAF-A745-03835AAD4A55}
+.imagebase 0x00400000
+.file alignment 0x00000200
+.stackreserve 0x00100000
+.subsystem 0x0003       // WINDOWS_CUI
+.corflags 0x00000001    //  ILONLY
+// Image base: 0x00AE0000
+
+
+// =============== CLASS MEMBERS DECLARATION ===================
+
+.class public abstract auto ansi sealed AbstractClass
+       extends [mscorlib]System.Object
+{
+  .custom instance void [FSharp.Core]Microsoft.FSharp.Core.CompilationMappingAttribute::.ctor(valuetype [FSharp.Core]Microsoft.FSharp.Core.SourceConstructFlags) = ( 01 00 07 00 00 00 00 00 ) 
+  .class abstract auto ansi serializable nested public X
+         extends [mscorlib]System.Object
+  {
+    .custom instance void [FSharp.Core]Microsoft.FSharp.Core.AbstractClassAttribute::.ctor() = ( 01 00 00 00 ) 
+    .custom instance void [FSharp.Core]Microsoft.FSharp.Core.CompilationMappingAttribute::.ctor(valuetype [FSharp.Core]Microsoft.FSharp.Core.SourceConstructFlags) = ( 01 00 03 00 00 00 00 00 ) 
+    .method public specialname rtspecialname 
+            instance void  .ctor(int32 i) cil managed
+    {
+      // 
+      .maxstack  8
+      .language '{AB4F38C9-B6E6-43BA-BE3B-58080B2CCCE3}', '{994B45C4-E6E9-11D2-903F-00C04FA302A1}', '{5A869D0B-6611-11D3-BD2A-0000F80849BD}'
+      .line 4,4 : 6,7 'D:\\source\\repos\\latkinfsharp\\tests\\fsharpqa\\Source\\CodeGen\\EmittedIL\\Misc\\AbstractClass.fs'
+      IL_0000:  ldarg.0
+      IL_0001:  callvirt   instance void [mscorlib]System.Object::.ctor()
+      IL_0006:  ldarg.0
+      IL_0007:  pop
+      IL_0008:  nop
+      IL_0009:  ret
+    } // end of method X::.ctor
+
+    .method assembly specialname rtspecialname 
+            instance void  .ctor() cil managed
+    {
+      // 
+      .maxstack  8
+      .line 5,5 : 22,26 ''
+      IL_0000:  nop
+      IL_0001:  ldarg.0
+      IL_0002:  ldc.i4.1
+      IL_0003:  callvirt   instance void AbstractClass/X::.ctor(int32)
+      IL_0008:  ret
+    } // end of method X::.ctor
+
+    .method assembly specialname rtspecialname 
+            instance void  .ctor(float32 f) cil managed
+    {
+      // 
+      .maxstack  8
+      .line 6,6 : 32,36 ''
+      IL_0000:  nop
+      IL_0001:  ldarg.0
+      IL_0002:  ldc.i4.1
+      IL_0003:  callvirt   instance void AbstractClass/X::.ctor(int32)
+      IL_0008:  ret
+    } // end of method X::.ctor
+
+  } // end of class X
+
+} // end of class AbstractClass
+
+.class private abstract auto ansi sealed '<StartupCode$AbstractClass>'.$AbstractClass
+       extends [mscorlib]System.Object
+{
+  .field static assembly int32 init@
+  .custom instance void [mscorlib]System.Diagnostics.DebuggerBrowsableAttribute::.ctor(valuetype [mscorlib]System.Diagnostics.DebuggerBrowsableState) = ( 01 00 00 00 00 00 00 00 ) 
+  .custom instance void [mscorlib]System.Runtime.CompilerServices.CompilerGeneratedAttribute::.ctor() = ( 01 00 00 00 ) 
+  .custom instance void [mscorlib]System.Diagnostics.DebuggerNonUserCodeAttribute::.ctor() = ( 01 00 00 00 ) 
+  .method public static void  main@() cil managed
+  {
+    .entrypoint
+    // 
+    .maxstack  8
+    .line 8,8 : 1,7 ''
+    IL_0000:  nop
+    IL_0001:  ldc.i4.0
+    IL_0002:  call       !!0 [FSharp.Core]Microsoft.FSharp.Core.Operators::Exit<class [FSharp.Core]Microsoft.FSharp.Core.Unit>(int32)
+    IL_0007:  pop
+    IL_0008:  ret
+  } // end of method $AbstractClass::main@
+
+} // end of class '<StartupCode$AbstractClass>'.$AbstractClass
+
+
+// =============================================================
+
+// 
diff --git a/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/env.lst b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/env.lst
index f844964128..d905658cce 100644
--- a/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/env.lst
+++ b/tests/fsharpqa/Source/CodeGen/EmittedIL/Misc/env.lst
@@ -52,3 +52,5 @@
 
 # Note that unlike other codegen tests this requires --optimize+ since we're testing for the prescence of inlined code
 ReqPP	SOURCE=LazyNoInline01.fs ISCFLAGS="-g --test:EmitFeeFeeAs100001 --optimize+" COMPILE_ONLY=1 POSTCMD="..\\CompareIL.cmd LazyNoInline01.exe NetFx40"	# LazyNoInline01.fs - NetFx40
+
+	SOURCE=AbstractClass.fs ISCFLAGS="-g --test:EmitFeeFeeAs100001 --optimize-" COMPILE_ONLY=1 POSTCMD="..\\CompareIL.cmd AbstractClass.exe"	# AbstractClass.fs
\ No newline at end of file