diff --git a/clang-tools-extra/clangd/Selection.cpp b/clang-tools-extra/clangd/Selection.cpp
--- a/clang-tools-extra/clangd/Selection.cpp
+++ b/clang-tools-extra/clangd/Selection.cpp
@@ -897,7 +897,7 @@
       if (CurrentNode != this)
         if (auto *DC = dyn_cast<DeclContext>(Current))
           return *DC;
-      return *Current->getDeclContext();
+      return *Current->getLexicalDeclContext();
     }
   }
   llvm_unreachable("A tree must always be rooted at TranslationUnitDecl.");
diff --git a/clang-tools-extra/clangd/unittests/SelectionTests.cpp b/clang-tools-extra/clangd/unittests/SelectionTests.cpp
--- a/clang-tools-extra/clangd/unittests/SelectionTests.cpp
+++ b/clang-tools-extra/clangd/unittests/SelectionTests.cpp
@@ -739,6 +739,21 @@
   EXPECT_EQ(1u, Seen) << "one tree for nontrivial selection";
 }
 
+TEST(SelectionTest, DeclContext) {
+  llvm::Annotations Test("namespace a { void $1^foo(); } void a::$2^foo();");
+  auto AST = TestTU::withCode(Test.code()).build();
+  {
+    auto ST = SelectionTree::createRight(AST.getASTContext(), AST.getTokens(),
+                                         Test.point("1"), Test.point("1"));
+    EXPECT_FALSE(ST.commonAncestor()->getDeclContext().isTranslationUnit());
+  }
+  {
+    auto ST = SelectionTree::createRight(AST.getASTContext(), AST.getTokens(),
+                                         Test.point("2"), Test.point("2"));
+    EXPECT_TRUE(ST.commonAncestor()->getDeclContext().isTranslationUnit());
+  }
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang