diff --git a/clang-tools-extra/clangd/FindTarget.cpp b/clang-tools-extra/clangd/FindTarget.cpp
--- a/clang-tools-extra/clangd/FindTarget.cpp
+++ b/clang-tools-extra/clangd/FindTarget.cpp
@@ -491,6 +491,13 @@
                                   llvm::SmallVector<const NamedDecl *, 1>(
                                       E->decls().begin(), E->decls().end())});
     }
+
+    void VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
+      Refs.push_back(ReferenceLoc{NestedNameSpecifierLoc(),
+                                  E->getPackLoc(),
+                                  /*IsDecl=*/false,
+                                  {E->getPack()}});
+    }
   };
 
   Visitor V;
diff --git a/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp b/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
--- a/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
+++ b/clang-tools-extra/clangd/unittests/SemanticHighlightingTests.cpp
@@ -625,6 +625,13 @@
 $InactiveCode[[]]      #else
       int $Variable[[Active2]];
       #endif
+    )cpp",
+      // Argument to 'sizeof...'
+      R"cpp(
+      template <typename... $TemplateParameter[[Elements]]>
+      struct $Class[[TupleSize]] {
+        static const int $StaticField[[size]] = sizeof...($TemplateParameter[[Elements]]);
+      };
     )cpp"};
   for (const auto &TestCase : TestCases) {
     checkHighlightings(TestCase);