diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 4a94055..eb5616d 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -20,6 +20,8 @@
 namespace clang {
 namespace format {
 
+namespace {
+
 /// \brief A parser that gathers additional information about tokens.
 ///
 /// The \c TokenAnnotator tries to match parenthesis and square brakets and
@@ -865,6 +867,8 @@
   FormatToken *Current;
 };
 
+} // end anonymous namespace
+
 void TokenAnnotator::annotate(AnnotatedLine &Line) {
   AnnotatingParser Parser(Line, Ident_in);
   Line.Type = Parser.parseLine();