diff --git a/src/Microsoft.AspNetCore.Razor.Language/DefaultRazorTagHelperBinderPhase.cs b/src/Microsoft.AspNetCore.Razor.Language/DefaultRazorTagHelperBinderPhase.cs
index b75ab9335c..7d9dfb7c6e 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/DefaultRazorTagHelperBinderPhase.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/DefaultRazorTagHelperBinderPhase.cs
@@ -58,9 +58,8 @@ namespace Microsoft.AspNetCore.Razor.Language
             var root = syntaxTree.Root;
             root = rewriter.Rewrite(root, errorSink);
 
-            // Temporary code while we're still using legacy diagnostics in the SyntaxTree.
             var errorList = new List<RazorDiagnostic>();
-            errorList.AddRange(errorSink.Errors.Select(error => RazorDiagnostic.Create(error)));
+            errorList.AddRange(errorSink.Errors);
 
             errorList.AddRange(descriptors.SelectMany(d => d.GetAllDiagnostics()));
 
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
index 6390d1ffc4..8a720db36b 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
@@ -1840,8 +1840,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             {
                 if (directiveErrorSink.Errors.Count > 0)
                 {
-                    var directiveDiagnostics = directiveErrorSink.Errors.Select(error => RazorDiagnostic.Create(error));
-                    directiveChunkGenerator.Diagnostics.AddRange(directiveDiagnostics);
+                    directiveChunkGenerator.Diagnostics.AddRange(directiveErrorSink.Errors);
                 }
 
                 Context.ErrorSink = savedErrorSink;
@@ -2223,17 +2222,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             }
             finally
             {
-                List<RazorDiagnostic> directiveErrors;
-                if (directiveErrorSink.Errors.Count > 0)
-                {
-                    directiveErrors = directiveErrorSink.Errors.Select(RazorDiagnostic.Create).ToList();
-                }
-                else
-                {
-                    directiveErrors = new List<RazorDiagnostic>();
-                }
-
-                Span.ChunkGenerator = chunkGeneratorFactory(directiveValue, directiveErrors);
+                Span.ChunkGenerator = chunkGeneratorFactory(directiveValue, directiveErrorSink.Errors.ToList());
                 Context.ErrorSink = savedErrorSink;
             }
 
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpLanguageCharacteristics.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpLanguageCharacteristics.cs
index 7a251cc7e9..b52d48cbf8 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpLanguageCharacteristics.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpLanguageCharacteristics.cs
@@ -74,7 +74,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return new CSharpTokenizer(source);
         }
 
-        protected override CSharpSymbol CreateSymbol(string content, CSharpSymbolType type, IReadOnlyList<RazorError> errors)
+        protected override CSharpSymbol CreateSymbol(string content, CSharpSymbolType type, IReadOnlyList<RazorDiagnostic> errors)
         {
             return new CSharpSymbol(content, type, errors);
         }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpSymbol.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpSymbol.cs
index cbb8cc9a21..21cd94915d 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpSymbol.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpSymbol.cs
@@ -11,7 +11,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         public CSharpSymbol(
             string content,
             CSharpSymbolType type)
-            : base(content, type, RazorError.EmptyArray)
+            : base(content, type, RazorDiagnostic.EmptyArray)
         {
             if (content == null)
             {
@@ -22,7 +22,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         public CSharpSymbol(
             string content,
             CSharpSymbolType type,
-            IReadOnlyList<RazorError> errors)
+            IReadOnlyList<RazorDiagnostic> errors)
             : base(content, type, errors)
         {
             if (content == null)
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpTokenizer.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpTokenizer.cs
index eb08ba8e2e..0b7816f2f6 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpTokenizer.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpTokenizer.cs
@@ -343,7 +343,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return base.GetSymbolContent(type);
         }
 
-        protected override CSharpSymbol CreateSymbol(string content, CSharpSymbolType type, IReadOnlyList<RazorError> errors)
+        protected override CSharpSymbol CreateSymbol(string content, CSharpSymbolType type, IReadOnlyList<RazorDiagnostic> errors)
         {
             return new CSharpSymbol(content, type, errors);
         }
@@ -547,10 +547,11 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             else if (EndOfFile)
             {
                 CurrentErrors.Add(
-                    new RazorError(
-                        LegacyResources.ParseError_Unterminated_String_Literal,
-                        CurrentStart,
-                        length: 1 /* end of file */));
+                    RazorDiagnostic.Create(
+                        new RazorError(
+                            LegacyResources.ParseError_Unterminated_String_Literal,
+                            CurrentStart,
+                            length: 1 /* end of file */)));
             }
             return Transition(CSharpTokenizerState.Data, EndSymbol(CSharpSymbolType.StringLiteral));
         }
@@ -576,10 +577,10 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             else if (EndOfFile || ParserHelpers.IsNewLine(CurrentCharacter))
             {
                 CurrentErrors.Add(
-                    new RazorError(
+                    RazorDiagnostic.Create(new RazorError(
                         LegacyResources.ParseError_Unterminated_String_Literal,
                         CurrentStart,
-                        length: 1 /* " */));
+                        length: 1 /* " */)));
             }
             else
             {
@@ -595,10 +596,10 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             if (EndOfFile)
             {
                 CurrentErrors.Add(
-                    new RazorError(
+                    RazorDiagnostic.Create(new RazorError(
                         LegacyResources.ParseError_BlockComment_Not_Terminated,
                         CurrentStart,
-                        length: 1 /* end of file */));
+                        length: 1 /* end of file */)));
                 return Transition(CSharpTokenizerState.Data, EndSymbol(CSharpSymbolType.Comment));
             }
             if (CurrentCharacter == '*')
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/ErrorSink.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/ErrorSink.cs
index c8219dda5a..93cce597f1 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/ErrorSink.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/ErrorSink.cs
@@ -6,40 +6,41 @@ using System.Collections.Generic;
 namespace Microsoft.AspNetCore.Razor.Language.Legacy
 {
     /// <summary>
-    /// Used to manage <see cref="RazorError"/>s encountered during the Razor parsing phase.
+    /// Used to manage <see cref="RazorDiagnostic"/>s encountered during the Razor parsing phase.
     /// </summary>
     internal class ErrorSink
     {
-        private readonly List<RazorError> _errors;
+        private readonly List<RazorDiagnostic> _errors;
 
         /// <summary>
         /// Instantiates a new instance of <see cref="ErrorSink"/>.
         /// </summary>
         public ErrorSink()
         {
-            _errors = new List<RazorError>();
+            _errors = new List<RazorDiagnostic>();
         }
 
         /// <summary>
-        /// <see cref="RazorError"/>s collected.
+        /// <see cref="RazorDiagnostic"/>s collected.
         /// </summary>
-        public IReadOnlyList<RazorError> Errors => _errors;
+        public IReadOnlyList<RazorDiagnostic> Errors => _errors;
 
         /// <summary>
         /// Tracks the given <paramref name="error"/>.
         /// </summary>
         /// <param name="error">The <see cref="RazorError"/> to track.</param>
-        public void OnError(RazorError error) =>_errors.Add(error);
+        public void OnError(RazorDiagnostic error) =>_errors.Add(error);
 
         /// <summary>
-        /// Creates and tracks a new <see cref="RazorError"/>.
+        /// Creates and tracks a new <see cref="RazorDiagnostic"/>.
         /// </summary>
         /// <param name="location"><see cref="SourceLocation"/> of the error.</param>
         /// <param name="message">A message describing the error.</param>
         /// <param name="length">The length of the error.</param>
+        /// <remarks>This is temporary. It will be removed once we get rid of <see cref="LegacyRazorDiagnostic"/>.</remarks>
         public void OnError(SourceLocation location, string message, int length)
         {
-            var error = new RazorError(message, location, length);
+            var error = RazorDiagnostic.Create(new RazorError(message, location, length));
             _errors.Add(error);
         }
     }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlLanguageCharacteristics.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlLanguageCharacteristics.cs
index 70d7929736..1021a6ac90 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlLanguageCharacteristics.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlLanguageCharacteristics.cs
@@ -119,7 +119,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             }
         }
 
-        protected override HtmlSymbol CreateSymbol(string content, HtmlSymbolType type, IReadOnlyList<RazorError> errors)
+        protected override HtmlSymbol CreateSymbol(string content, HtmlSymbolType type, IReadOnlyList<RazorDiagnostic> errors)
         {
             return new HtmlSymbol(content, type, errors);
         }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlSymbol.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlSymbol.cs
index da308bcc14..f41f323d1d 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlSymbol.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlSymbol.cs
@@ -9,7 +9,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
     internal class HtmlSymbol : SymbolBase<HtmlSymbolType>
     {
         public HtmlSymbol(string content, HtmlSymbolType type)
-            : base(content, type, RazorError.EmptyArray)
+            : base(content, type, RazorDiagnostic.EmptyArray)
         {
             if (content == null)
             {
@@ -20,7 +20,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         public HtmlSymbol(
             string content,
             HtmlSymbolType type,
-            IReadOnlyList<RazorError> errors)
+            IReadOnlyList<RazorDiagnostic> errors)
             : base(content, type, errors)
         {
             if (content == null)
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlTokenizer.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlTokenizer.cs
index 0b3af2d407..df9671d1b7 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlTokenizer.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlTokenizer.cs
@@ -36,7 +36,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             get { return HtmlSymbolType.RazorCommentStar; }
         }
 
-        protected override HtmlSymbol CreateSymbol(string content, HtmlSymbolType type, IReadOnlyList<RazorError> errors)
+        protected override HtmlSymbol CreateSymbol(string content, HtmlSymbolType type, IReadOnlyList<RazorDiagnostic> errors)
         {
             return new HtmlSymbol(content, type, errors);
         }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/LanguageCharacteristics.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/LanguageCharacteristics.cs
index 02b5864458..23d5f037d0 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/LanguageCharacteristics.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/LanguageCharacteristics.cs
@@ -86,7 +86,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         public virtual Tuple<TSymbol, TSymbol> SplitSymbol(TSymbol symbol, int splitAt, TSymbolType leftType)
         {
-            var left = CreateSymbol(symbol.Content.Substring(0, splitAt), leftType, RazorError.EmptyArray);
+            var left = CreateSymbol(symbol.Content.Substring(0, splitAt), leftType, RazorDiagnostic.EmptyArray);
 
             TSymbol right = null;
             if (splitAt < symbol.Content.Length)
@@ -104,6 +104,6 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             return type == KnownSymbolType.Unknown || !Equals(GetKnownSymbolType(type), GetKnownSymbolType(KnownSymbolType.Unknown));
         }
 
-        protected abstract TSymbol CreateSymbol(string content, TSymbolType type, IReadOnlyList<RazorError> errors);
+        protected abstract TSymbol CreateSymbol(string content, TSymbolType type, IReadOnlyList<RazorDiagnostic> errors);
     }
 }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/RazorParser.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/RazorParser.cs
index 2823ffd69d..8e79907b8c 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/RazorParser.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/RazorParser.cs
@@ -43,8 +43,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             
             var root = context.Builder.Build();
 
-            // Temporary code while we're still using legacy diagnostics in the SyntaxTree.
-            var diagnostics = context.ErrorSink.Errors.Select(error => RazorDiagnostic.Create(error));
+            var diagnostics = context.ErrorSink.Errors;
 
             return RazorSyntaxTree.Create(root, source, diagnostics, Options);
         }
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/SymbolBase.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/SymbolBase.cs
index b0a772e85d..c1caebb988 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/SymbolBase.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/SymbolBase.cs
@@ -13,7 +13,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         protected SymbolBase(
             string content,
             TType type,
-            IReadOnlyList<RazorError> errors)
+            IReadOnlyList<RazorDiagnostic> errors)
         {
             if (content == null)
             {
@@ -27,7 +27,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         public Span Parent { get; set; }
 
-        public IReadOnlyList<RazorError> Errors { get; }
+        public IReadOnlyList<RazorDiagnostic> Errors { get; }
 
         public string Content { get; }
 
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/Tokenizer.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/Tokenizer.cs
index fdc0deb956..465754f6d5 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/Tokenizer.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/Tokenizer.cs
@@ -21,11 +21,11 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
             Source = source;
             Buffer = new StringBuilder();
-            CurrentErrors = new List<RazorError>();
+            CurrentErrors = new List<RazorDiagnostic>();
             StartSymbol();
         }
 
-        protected List<RazorError> CurrentErrors { get; }
+        protected List<RazorDiagnostic> CurrentErrors { get; }
 
         protected abstract int StartState { get; }
 
@@ -64,7 +64,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         public SourceLocation CurrentStart { get; private set; }
 
-        protected abstract TSymbol CreateSymbol(string content, TSymbolType type, IReadOnlyList<RazorError> errors);
+        protected abstract TSymbol CreateSymbol(string content, TSymbolType type, IReadOnlyList<RazorDiagnostic> errors);
 
         protected abstract StateResult Dispatch();
 
@@ -205,7 +205,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             if (HaveContent)
             {
                 // Perf: Don't allocate a new errors array unless necessary.
-                var errors = CurrentErrors.Count == 0 ? RazorError.EmptyArray : new RazorError[CurrentErrors.Count];
+                var errors = CurrentErrors.Count == 0 ? RazorDiagnostic.EmptyArray : new RazorDiagnostic[CurrentErrors.Count];
                 for (var i = 0; i < CurrentErrors.Count; i++)
                 {
                     errors[i] = CurrentErrors[i];
diff --git a/src/Microsoft.AspNetCore.Razor.Language/RazorDiagnostic.cs b/src/Microsoft.AspNetCore.Razor.Language/RazorDiagnostic.cs
index 0edb2fdf93..e5dbac402a 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/RazorDiagnostic.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/RazorDiagnostic.cs
@@ -8,6 +8,7 @@ namespace Microsoft.AspNetCore.Razor.Language
 {
     public abstract class RazorDiagnostic : IEquatable<RazorDiagnostic>, IFormattable
     {
+        internal static readonly RazorDiagnostic[] EmptyArray = new RazorDiagnostic[0];
         internal static readonly object[] EmptyArgs = new object[0];
 
         public abstract string Id { get; }
diff --git a/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TagHelperRewritingTestBase.cs b/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TagHelperRewritingTestBase.cs
index 8471aaf23a..6be1b3a5cb 100644
--- a/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TagHelperRewritingTestBase.cs
+++ b/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TagHelperRewritingTestBase.cs
@@ -63,7 +63,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
             var actualTree = parseTreeRewriter.Rewrite(syntaxTree.Root, errorSink);
 
-            var allErrors = syntaxTree.Diagnostics.Concat(errorSink.Errors.Select(error => RazorDiagnostic.Create(error)));
+            var allErrors = syntaxTree.Diagnostics.Concat(errorSink.Errors);
             var actualErrors = allErrors
                 .OrderBy(error => error.Span.AbsoluteIndex)
                 .ToList();
diff --git a/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TokenizerLookaheadTest.cs b/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TokenizerLookaheadTest.cs
index d8b98becfd..6abd70ad3e 100644
--- a/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TokenizerLookaheadTest.cs
+++ b/test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/TokenizerLookaheadTest.cs
@@ -106,7 +106,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             protected override CSharpSymbol CreateSymbol(
                 string content,
                 CSharpSymbolType type,
-                IReadOnlyList<RazorError> errors)
+                IReadOnlyList<RazorDiagnostic> errors)
             {
                 throw new NotImplementedException();
             }
diff --git a/test/Microsoft.AspNetCore.Razor.Test.Common/Language/Legacy/ParserTestBase.cs b/test/Microsoft.AspNetCore.Razor.Test.Common/Language/Legacy/ParserTestBase.cs
index f91e4c65aa..3e25f1c0d7 100644
--- a/test/Microsoft.AspNetCore.Razor.Test.Common/Language/Legacy/ParserTestBase.cs
+++ b/test/Microsoft.AspNetCore.Razor.Test.Common/Language/Legacy/ParserTestBase.cs
@@ -60,7 +60,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             markupParser.ParseDocument();
 
             var root = context.Builder.Build();
-            var diagnostics = context.ErrorSink.Errors?.Select(error => RazorDiagnostic.Create(error));
+            var diagnostics = context.ErrorSink.Errors;
 
             var codeDocument = RazorCodeDocument.Create(source);
 
@@ -90,7 +90,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             parser.ParseBlock();
 
             var root = context.Builder.Build();
-            var diagnostics = context.ErrorSink.Errors?.Select(error => RazorDiagnostic.Create(error));
+            var diagnostics = context.ErrorSink.Errors;
 
             return RazorSyntaxTree.Create(root, source, diagnostics, options);
         }
@@ -120,7 +120,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             parser.ParseBlock();
 
             var root = context.Builder.Build();
-            var diagnostics = context.ErrorSink.Errors?.Select(error => RazorDiagnostic.Create(error));
+            var diagnostics = context.ErrorSink.Errors;
 
             return RazorSyntaxTree.Create(root, source, diagnostics, options);
         }