diff --git a/clang/lib/Format/UnwrappedLineParser.cpp b/clang/lib/Format/UnwrappedLineParser.cpp
--- a/clang/lib/Format/UnwrappedLineParser.cpp
+++ b/clang/lib/Format/UnwrappedLineParser.cpp
@@ -2119,6 +2119,7 @@
     case tok::amp:
     case tok::star:
     case tok::kw_const:
+    case tok::kw_constexpr:
     case tok::comma:
     case tok::less:
     case tok::greater:
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -894,6 +894,13 @@
   EXPECT_TOKEN(Tokens[9], tok::l_brace, TT_ObjCBlockLBrace);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandsLambdas) {
+  auto Tokens = annotate("[]() constexpr {}");
+  ASSERT_EQ(Tokens.size(), 8u) << Tokens;
+  EXPECT_TOKEN(Tokens[0], tok::l_square, TT_LambdaLSquare);
+  EXPECT_TOKEN(Tokens[5], tok::l_brace, TT_LambdaLBrace);
+}
+
 } // namespace
 } // namespace format
 } // namespace clang