diff --git a/clang-tools-extra/clangd/refactor/tweaks/AddUsing.cpp b/clang-tools-extra/clangd/refactor/tweaks/AddUsing.cpp
--- a/clang-tools-extra/clangd/refactor/tweaks/AddUsing.cpp
+++ b/clang-tools-extra/clangd/refactor/tweaks/AddUsing.cpp
@@ -141,10 +141,12 @@
   }
 
   // No relevant "using" statements. Try the nearest namespace level.
-  const auto *NS = Inputs.ASTSelection.commonAncestor()
-                       ->getDeclContext()
-                       .getEnclosingNamespaceContext();
-  if (auto *ND = dyn_cast<NamespaceDecl>(NS)) {
+  const DeclContext *ParentDeclCtx =
+      &Inputs.ASTSelection.commonAncestor()->getDeclContext();
+  while (ParentDeclCtx && !ParentDeclCtx->isFileContext()) {
+    ParentDeclCtx = ParentDeclCtx->getLexicalParent();
+  }
+  if (auto *ND = llvm::dyn_cast_or_null<NamespaceDecl>(ParentDeclCtx)) {
     auto Toks = Inputs.AST->getTokens().expandedTokens(ND->getSourceRange());
     const auto *Tok = llvm::find_if(Toks, [](const syntax::Token &Tok) {
       return Tok.kind() == tok::l_brace;
diff --git a/clang-tools-extra/clangd/unittests/TweakTests.cpp b/clang-tools-extra/clangd/unittests/TweakTests.cpp
--- a/clang-tools-extra/clangd/unittests/TweakTests.cpp
+++ b/clang-tools-extra/clangd/unittests/TweakTests.cpp
@@ -2663,6 +2663,23 @@
 
 void fun() {
   CALL(ff);
+})cpp"},
+            // Parent namespace != lexical parent namespace
+            {R"cpp(
+#include "test.hpp"
+namespace foo { void fun(); }
+
+void foo::fun() {
+  one::two::f^f();
+})cpp",
+             R"cpp(
+#include "test.hpp"
+using one::two::ff;
+
+namespace foo { void fun(); }
+
+void foo::fun() {
+  ff();
 })cpp"}};
   llvm::StringMap<std::string> EditedFiles;
   for (const auto &Case : Cases) {