diff --git a/clang-tools-extra/clangd/XRefs.cpp b/clang-tools-extra/clangd/XRefs.cpp
--- a/clang-tools-extra/clangd/XRefs.cpp
+++ b/clang-tools-extra/clangd/XRefs.cpp
@@ -1310,6 +1310,8 @@
       QueryKind = RelationKind::BaseOf;
     }
   }
+  if (IDs.empty())
+    return {};
   return findImplementors(std::move(IDs), QueryKind, Index, *MainFilePath);
 }