diff --git a/clang/lib/Tooling/Syntax/Tree.cpp b/clang/lib/Tooling/Syntax/Tree.cpp
--- a/clang/lib/Tooling/Syntax/Tree.cpp
+++ b/clang/lib/Tooling/Syntax/Tree.cpp
@@ -305,6 +305,7 @@
   case syntax::NodeKind::NestedNameSpecifier:
   case syntax::NodeKind::CallArguments:
   case syntax::NodeKind::ParameterDeclarationList:
+  case syntax::NodeKind::DeclaratorList:
     return true;
   default:
     return false;
@@ -405,6 +406,7 @@
     return clang::tok::coloncolon;
   case NodeKind::CallArguments:
   case NodeKind::ParameterDeclarationList:
+  case NodeKind::DeclaratorList:
     return clang::tok::comma;
   default:
     llvm_unreachable("This is not a subclass of List, thus "
@@ -418,6 +420,7 @@
     return TerminationKind::Terminated;
   case NodeKind::CallArguments:
   case NodeKind::ParameterDeclarationList:
+  case NodeKind::DeclaratorList:
     return TerminationKind::Separated;
   default:
     llvm_unreachable("This is not a subclass of List, thus "
@@ -433,6 +436,8 @@
     return true;
   case NodeKind::ParameterDeclarationList:
     return true;
+  case NodeKind::DeclaratorList:
+    return true;
   default:
     llvm_unreachable("This is not a subclass of List, thus canBeEmpty() "
                      "cannot be called");