diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
index 960cc7cf04..e29710acd1 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/CSharpCodeParser.cs
@@ -54,7 +54,6 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
 
         private Dictionary<string, Action> _directiveParsers = new Dictionary<string, Action>(StringComparer.Ordinal);
         private Dictionary<CSharpKeyword, Action<bool>> _keywordParsers = new Dictionary<CSharpKeyword, Action<bool>>();
-        private HashSet<string> _seenDirectives = new HashSet<string>(StringComparer.Ordinal);
 
         public CSharpCodeParser(ParserContext context)
             : this(directives: Enumerable.Empty<DirectiveDescriptor>(), context: context)
@@ -95,7 +94,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
                 _directiveParsers.Add(directive, () =>
                 {
                     handler();
-                    _seenDirectives.Add(directive);
+                    Context.SeenDirectives.Add(directive);
                 });
 
                 Keywords.Add(directive);
@@ -1781,7 +1780,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
         {
             if (descriptor.Usage == DirectiveUsage.FileScopedSinglyOccurring)
             {
-                if (_seenDirectives.Contains(descriptor.Directive))
+                if (Context.SeenDirectives.Contains(descriptor.Directive))
                 {
                     UsageError(Resources.FormatDuplicateDirective(descriptor.Directive));
                     return;
diff --git a/src/Microsoft.AspNetCore.Razor.Language/Legacy/ParserContext.cs b/src/Microsoft.AspNetCore.Razor.Language/Legacy/ParserContext.cs
index 897504a300..1207616604 100644
--- a/src/Microsoft.AspNetCore.Razor.Language/Legacy/ParserContext.cs
+++ b/src/Microsoft.AspNetCore.Razor.Language/Legacy/ParserContext.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 
@@ -25,12 +26,15 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
             ParseOnlyLeadingDirectives = options.ParseOnlyLeadingDirectives;
             Builder = new SyntaxTreeBuilder();
             ErrorSink = new ErrorSink();
+            SeenDirectives = new HashSet<string>(StringComparer.Ordinal);
         }
 
         public SyntaxTreeBuilder Builder { get; }
 
         public ErrorSink ErrorSink { get; set; }
 
+        public HashSet<string> SeenDirectives { get; }
+
         public ITextDocument Source { get; }
 
         public RazorSourceDocument SourceDocument { get; }