diff --git a/src/fsharp/PatternMatchCompilation.fs b/src/fsharp/PatternMatchCompilation.fs
index 0bf4df1c2569..f1897b992d96 100644
--- a/src/fsharp/PatternMatchCompilation.fs
+++ b/src/fsharp/PatternMatchCompilation.fs
@@ -528,11 +528,7 @@ let (|ConstNeedsDefaultCase|_|) c =
     | Const.Decimal _
     | Const.String _
     | Const.Single _
-    |  Const.Double _
-    | Const.SByte _
-    | Const.Byte _
-    | Const.Int16 _
-    | Const.UInt16 _
+    | Const.Double _
     | Const.Int32 _
     | Const.UInt32 _
     | Const.Int64 _
@@ -1081,9 +1077,12 @@ let CompilePatternBasic
             match getDiscrimOfPattern p with
             | Some discrim -> List.exists (isDiscrimSubsumedBy g amap exprm discrim) simulSetOfDiscrims
             | None -> false
-
         match simulSetOfDiscrims with
         | DecisionTreeTest.Const (Const.Bool _b) :: _ when simulSetOfCases.Length = 2 ->  None
+        | DecisionTreeTest.Const (Const.Byte _) :: _  when simulSetOfCases.Length = 256 ->  None
+        | DecisionTreeTest.Const (Const.SByte _) :: _  when simulSetOfCases.Length = 256 ->  None
+        | DecisionTreeTest.Const (Const.Int16 _) :: _  when simulSetOfCases.Length = 65536 ->  None
+        | DecisionTreeTest.Const (Const.UInt16 _) :: _  when simulSetOfCases.Length = 65536 ->  None
         | DecisionTreeTest.Const (Const.Unit) :: _  ->  None
         | DecisionTreeTest.UnionCase (ucref, _) :: _ when  simulSetOfCases.Length = ucref.TyconRef.UnionCasesArray.Length -> None
         | DecisionTreeTest.ActivePatternCase _ :: _ -> error(InternalError("DecisionTreeTest.ActivePatternCase should have been eliminated", matchm))