diff --git a/Source/DGrok.Framework/Framework/TokenFilter.cs b/Source/DGrok.Framework/Framework/TokenFilter.cs
index f93665b..c8186be 100644
--- a/Source/DGrok.Framework/Framework/TokenFilter.cs
+++ b/Source/DGrok.Framework/Framework/TokenFilter.cs
@@ -86,6 +86,7 @@ public TokenFilter(IEnumerable<Token> tokens, CompilerDefines compilerDefines,
             _directiveTypes["EXTENDEDSYNTAX"] = DirectiveType.Ignored;
             _directiveTypes["EXTENSION"] = DirectiveType.Ignored;
             _directiveTypes["FINITEFLOAT"] = DirectiveType.Ignored;
+            _directiveTypes["HIGHCHARUNICODE"] = DirectiveType.Ignored;
             _directiveTypes["HINTS"] = DirectiveType.Ignored;
             _directiveTypes["I"] = DirectiveType.PossibleInclude;
             _directiveTypes["IMAGEBASE"] = DirectiveType.Ignored;
diff --git a/Source/DGrok.Tests/TokenFilterTests.cs b/Source/DGrok.Tests/TokenFilterTests.cs
index e23a715..f9be602 100644
--- a/Source/DGrok.Tests/TokenFilterTests.cs
+++ b/Source/DGrok.Tests/TokenFilterTests.cs
@@ -95,6 +95,12 @@ public void CPlusPlusBuilderCompilerDirectivesAreIgnored()
             Assert.That("{$NOINCLUDE Foo}", LexesAndFiltersAs());
         }
         [Test]
+        public void HighCharUnicodeCompilerDirectivesAreIgnored()
+        {
+            Assert.That("{$HIGHCHARUNICODE ON}", LexesAndFiltersAs());
+            Assert.That("{$HIGHCHARUNICODE OFF}", LexesAndFiltersAs());
+        }
+        [Test]
         public void IfDefTrue()
         {
             Assert.That("0{$IFDEF TRUE}1{$ENDIF}2", LexesAndFiltersAs(