diff --git a/clang/unittests/Format/TestLexer.h b/clang/unittests/Format/TestLexer.h
index 6a3d0bdedcee0..8b5949b32fc9e 100644
--- a/clang/unittests/Format/TestLexer.h
+++ b/clang/unittests/Format/TestLexer.h
@@ -61,9 +61,7 @@ class TestLexer : public UnwrappedLineConsumer {
             std::vector<std::unique_ptr<llvm::MemoryBuffer>> &Buffers,
             FormatStyle Style = getLLVMStyle())
       : Allocator(Allocator), Buffers(Buffers), Style(Style),
-        SourceMgr("test.cpp", ""), IdentTable(LangOpts) {
-    assert(LangOpts.CPlusPlus);
-  }
+        SourceMgr("test.cpp", ""), IdentTable(getFormattingLangOpts(Style)) {}
 
   TokenList lex(llvm::StringRef Code) {
     FormatTokenLexer Lex = getNewLexer(Code);