Index: change-namespace/ChangeNamespace.h
===================================================================
--- change-namespace/ChangeNamespace.h
+++ change-namespace/ChangeNamespace.h
@@ -50,6 +50,7 @@
   // files matching `FilePattern`.
   ChangeNamespaceTool(
       llvm::StringRef OldNs, llvm::StringRef NewNs, llvm::StringRef FilePattern,
+      llvm::ArrayRef<const char *> WhiteListedSymbolPatterns,
       std::map<std::string, tooling::Replacements> *FileToReplacements,
       llvm::StringRef FallbackStyle = "LLVM");
 
@@ -164,6 +165,9 @@
   // CallExpr and one as DeclRefExpr), we record all DeclRefExpr's that have
   // been processed so that we don't handle them twice.
   llvm::SmallPtrSet<const clang::DeclRefExpr*, 16> ProcessedFuncRefs;
+  // Patterns of symbol names whose references are not expected to be updated
+  // when changing namespaces around them.
+  std::vector<llvm::Regex> WhiteListedSymbolRegexes;
 };
 
 } // namespace change_namespace
Index: change-namespace/ChangeNamespace.cpp
===================================================================
--- change-namespace/ChangeNamespace.cpp
+++ change-namespace/ChangeNamespace.cpp
@@ -290,6 +290,7 @@
 
 ChangeNamespaceTool::ChangeNamespaceTool(
     llvm::StringRef OldNs, llvm::StringRef NewNs, llvm::StringRef FilePattern,
+    llvm::ArrayRef<const char *> WhiteListedSymbolPatterns,
     std::map<std::string, tooling::Replacements> *FileToReplacements,
     llvm::StringRef FallbackStyle)
     : FallbackStyle(FallbackStyle), FileToReplacements(*FileToReplacements),
@@ -308,6 +309,11 @@
   }
   DiffOldNamespace = joinNamespaces(OldNsSplitted);
   DiffNewNamespace = joinNamespaces(NewNsSplitted);
+
+  for (const char *Pattern : WhiteListedSymbolPatterns) {
+    llvm::errs() << "Whitelisting " << Pattern << "\n";
+    WhiteListedSymbolRegexes.emplace_back(Pattern);
+  }
 }
 
 void ChangeNamespaceTool::registerMatchers(ast_matchers::MatchFinder *Finder) {
@@ -736,6 +742,9 @@
           Result.SourceManager->getSpellingLoc(End)),
       *Result.SourceManager, Result.Context->getLangOpts());
   std::string FromDeclName = FromDecl->getQualifiedNameAsString();
+  for (llvm::Regex &RE : WhiteListedSymbolRegexes)
+    if (RE.match(FromDeclName))
+      return;
   std::string ReplaceName =
       getShortestQualifiedNameInNamespace(FromDeclName, NewNs);
   // Checks if there is any using namespace declarations that can shorten the
Index: change-namespace/tool/ClangChangeNamespace.cpp
===================================================================
--- change-namespace/tool/ClangChangeNamespace.cpp
+++ change-namespace/tool/ClangChangeNamespace.cpp
@@ -73,6 +73,10 @@
                            cl::desc("The style name used for reformatting."),
                            cl::init("LLVM"), cl::cat(ChangeNamespaceCategory));
 
+// Patterns of symbol names whose references are not expected to be updated when
+// changing namespaces around them.
+constexpr const char *WhiteListedSymbolPatterns[] = {"^std::.*$"};
+
 } // anonymous namespace
 
 int main(int argc, const char **argv) {
@@ -82,7 +86,8 @@
   const auto &Files = OptionsParser.getSourcePathList();
   tooling::RefactoringTool Tool(OptionsParser.getCompilations(), Files);
   change_namespace::ChangeNamespaceTool NamespaceTool(
-      OldNamespace, NewNamespace, FilePattern, &Tool.getReplacements(), Style);
+      OldNamespace, NewNamespace, FilePattern, WhiteListedSymbolPatterns,
+      &Tool.getReplacements(), Style);
   ast_matchers::MatchFinder Finder;
   NamespaceTool.registerMatchers(&Finder);
   std::unique_ptr<tooling::FrontendActionFactory> Factory =
Index: test/change-namespace/Inputs/fake-std.h
===================================================================
--- /dev/null
+++ test/change-namespace/Inputs/fake-std.h
@@ -0,0 +1,5 @@
+namespace std {
+  class STD {};
+}
+
+using namespace std;
Index: test/change-namespace/white-list.cpp
===================================================================
--- /dev/null
+++ test/change-namespace/white-list.cpp
@@ -0,0 +1,18 @@
+// RUN: clang-change-namespace -old_namespace "na::nb" -new_namespace "x::y" --file_pattern ".*" %s -- | sed 's,// CHECK.*,,' | FileCheck %s
+
+#include "Inputs/fake-std.h"
+
+// CHECK: namespace x {
+// CHECK-NEXT: namespace y {
+namespace na {
+namespace nb {
+void f() {
+  std::STD x1;
+  STD x2;
+// CHECK: {{^}}  std::STD x1;{{$}}
+// CHECK-NEXT: {{^}}  STD x2;{{$}}
+}
+// CHECK: } // namespace y
+// CHECK-NEXT: } // namespace x
+}
+}
Index: unittests/change-namespace/ChangeNamespaceTests.cpp
===================================================================
--- unittests/change-namespace/ChangeNamespaceTests.cpp
+++ unittests/change-namespace/ChangeNamespaceTests.cpp
@@ -37,8 +37,10 @@
     clang::FileID ID = Context.createInMemoryFile(FileName, Code);
 
     std::map<std::string, tooling::Replacements> FileToReplacements;
+    constexpr const char *WhiteListedSymbolPatterns[] = {"^std::.*$"};
     change_namespace::ChangeNamespaceTool NamespaceTool(
-        OldNamespace, NewNamespace, FilePattern, &FileToReplacements);
+        OldNamespace, NewNamespace, FilePattern, WhiteListedSymbolPatterns,
+        &FileToReplacements);
     ast_matchers::MatchFinder Finder;
     NamespaceTool.registerMatchers(&Finder);
     std::unique_ptr<tooling::FrontendActionFactory> Factory =