diff --git a/clang-tools-extra/clangd/AST.cpp b/clang-tools-extra/clangd/AST.cpp
--- a/clang-tools-extra/clangd/AST.cpp
+++ b/clang-tools-extra/clangd/AST.cpp
@@ -119,17 +119,16 @@
       (void)ReachedNS;
       NNS = NestedNameSpecifier::Create(Context, nullptr, false,
                                         TD->getTypeForDecl());
-    } else {
+    } else if (auto *NSD = llvm::dyn_cast<NamespaceDecl>(CurContext)) {
       ReachedNS = true;
-      auto *NSD = llvm::cast<NamespaceDecl>(CurContext);
       NNS = NestedNameSpecifier::Create(Context, nullptr, NSD);
-      // Anonymous and inline namespace names are not spelled while qualifying a
-      // name, so skip those.
+      // Anonymous and inline namespace names are not spelled while qualifying
+      // a name, so skip those.
       if (NSD->isAnonymousNamespace() || NSD->isInlineNamespace())
         continue;
     }
     // Stop if this namespace is already visible at DestContext.
-    if (IsVisible(NNS))
+    if (!NNS || IsVisible(NNS))
       break;
 
     Parents.push_back(NNS);