diff --git a/clang-tools-extra/clangd/ClangdLSPServer.cpp b/clang-tools-extra/clangd/ClangdLSPServer.cpp
--- a/clang-tools-extra/clangd/ClangdLSPServer.cpp
+++ b/clang-tools-extra/clangd/ClangdLSPServer.cpp
@@ -87,7 +87,7 @@
 std::vector<std::vector<std::string>> buildHighlightScopeLookupTable() {
   std::vector<std::vector<std::string>> LookupTable;
   // HighlightingKind is using as the index.
-  for (int KindValue = 0; KindValue < (int)HighlightingKind::NumKinds;
+  for (int KindValue = 0; KindValue <= (int)HighlightingKind::LastKind;
        ++KindValue)
     LookupTable.push_back({toTextMateScope((HighlightingKind)(KindValue))});
   return LookupTable;
diff --git a/clang-tools-extra/clangd/SemanticHighlighting.h b/clang-tools-extra/clangd/SemanticHighlighting.h
--- a/clang-tools-extra/clangd/SemanticHighlighting.h
+++ b/clang-tools-extra/clangd/SemanticHighlighting.h
@@ -41,7 +41,7 @@
   Primitive,
   Macro,
 
-  NumKinds,
+  LastKind = Macro
 };
 llvm::raw_ostream& operator<<(llvm::raw_ostream &OS, HighlightingKind K);
 
diff --git a/clang-tools-extra/clangd/SemanticHighlighting.cpp b/clang-tools-extra/clangd/SemanticHighlighting.cpp
--- a/clang-tools-extra/clangd/SemanticHighlighting.cpp
+++ b/clang-tools-extra/clangd/SemanticHighlighting.cpp
@@ -387,9 +387,8 @@
     return OS << "Primitive";
   case HighlightingKind::Macro:
     return OS << "Macro";
-  case HighlightingKind::NumKinds:
-    llvm_unreachable("NumKinds is not a valid HighlightingKind");
   }
+  llvm_unreachable("invalid HighlightingKind");
 }
 
 std::vector<LineHighlightings>
@@ -515,8 +514,6 @@
     return "storage.type.primitive.cpp";
   case HighlightingKind::Macro:
     return "entity.name.function.preprocessor.cpp";
-  case HighlightingKind::NumKinds:
-    llvm_unreachable("must not pass NumKinds to the function");
   }
   llvm_unreachable("unhandled HighlightingKind");
 }