diff --git a/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.Generated.cs b/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.Generated.cs
index 63eb6db9ad..f1e7b7974a 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.Generated.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.Generated.cs
@@ -586,22 +586,6 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             }
         }
         
-        private static int BitCount(long value)
-        {
-            // see https://github.com/dotnet/corefx/blob/master/src/System.Reflection.Metadata/src/System/Reflection/Internal/Utilities/BitArithmetic.cs
-
-            const ulong Mask01010101 = 0x5555555555555555UL;
-            const ulong Mask00110011 = 0x3333333333333333UL;
-            const ulong Mask00001111 = 0x0F0F0F0F0F0F0F0FUL;
-            const ulong Mask00000001 = 0x0101010101010101UL;
-
-            var v = (ulong)value;
-
-            v = v - ((v >> 1) & Mask01010101);
-            v = (v & Mask00110011) + ((v >> 2) & Mask00110011);
-            return (int)(unchecked(((v + (v >> 4)) & Mask00001111) * Mask00000001) >> 56);
-        }
-
         protected override int GetCountFast()
         {
             return BitCount(_bits) + (MaybeUnknown?.Count ?? 0);
@@ -5428,22 +5412,6 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             }
         }
         
-        private static int BitCount(long value)
-        {
-            // see https://github.com/dotnet/corefx/blob/master/src/System.Reflection.Metadata/src/System/Reflection/Internal/Utilities/BitArithmetic.cs
-
-            const ulong Mask01010101 = 0x5555555555555555UL;
-            const ulong Mask00110011 = 0x3333333333333333UL;
-            const ulong Mask00001111 = 0x0F0F0F0F0F0F0F0FUL;
-            const ulong Mask00000001 = 0x0101010101010101UL;
-
-            var v = (ulong)value;
-
-            v = v - ((v >> 1) & Mask01010101);
-            v = (v & Mask00110011) + ((v >> 2) & Mask00110011);
-            return (int)(unchecked(((v + (v >> 4)) & Mask00001111) * Mask00000001) >> 56);
-        }
-
         protected override int GetCountFast()
         {
             return BitCount(_bits) + (MaybeUnknown?.Count ?? 0);
diff --git a/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.cs b/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.cs
index d188c692f2..18b19c114e 100644
--- a/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.cs
+++ b/src/Microsoft.AspNet.Server.Kestrel/Http/FrameHeaders.cs
@@ -45,6 +45,22 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             return StringValues.Concat(existing, append);
         }
 
+        protected static int BitCount(long value)
+        {
+            // see https://github.com/dotnet/corefx/blob/5965fd3756bc9dd9c89a27621eb10c6931126de2/src/System.Reflection.Metadata/src/System/Reflection/Internal/Utilities/BitArithmetic.cs
+
+            const ulong Mask01010101 = 0x5555555555555555UL;
+            const ulong Mask00110011 = 0x3333333333333333UL;
+            const ulong Mask00001111 = 0x0F0F0F0F0F0F0F0FUL;
+            const ulong Mask00000001 = 0x0101010101010101UL;
+
+            var v = (ulong)value;
+
+            v = v - ((v >> 1) & Mask01010101);
+            v = (v & Mask00110011) + ((v >> 2) & Mask00110011);
+            return (int)(unchecked(((v + (v >> 4)) & Mask00001111) * Mask00000001) >> 56);
+        }
+
         protected virtual int GetCountFast()
         { throw new NotImplementedException(); }
 
diff --git a/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/KnownHeaders.cs b/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/KnownHeaders.cs
index e1d6832675..759d6dacf8 100644
--- a/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/KnownHeaders.cs
+++ b/tools/Microsoft.AspNet.Server.Kestrel.GeneratedCode/KnownHeaders.cs
@@ -192,22 +192,6 @@ namespace Microsoft.AspNet.Server.Kestrel.Http
             }}
         }}
         ")}
-        private static int BitCount(long value)
-        {{
-            // see https://github.com/dotnet/corefx/blob/master/src/System.Reflection.Metadata/src/System/Reflection/Internal/Utilities/BitArithmetic.cs
-
-            const ulong Mask01010101 = 0x5555555555555555UL;
-            const ulong Mask00110011 = 0x3333333333333333UL;
-            const ulong Mask00001111 = 0x0F0F0F0F0F0F0F0FUL;
-            const ulong Mask00000001 = 0x0101010101010101UL;
-
-            var v = (ulong)value;
-
-            v = v - ((v >> 1) & Mask01010101);
-            v = (v & Mask00110011) + ((v >> 2) & Mask00110011);
-            return (int)(unchecked(((v + (v >> 4)) & Mask00001111) * Mask00000001) >> 56);
-        }}
-
         protected override int GetCountFast()
         {{
             return BitCount(_bits) + (MaybeUnknown?.Count ?? 0);