diff --git a/clangd/refactor/tweaks/ExtractFunction.cpp b/clangd/refactor/tweaks/ExtractFunction.cpp
index 1ae9fc0..4b28416 100644
--- a/clangd/refactor/tweaks/ExtractFunction.cpp
+++ b/clangd/refactor/tweaks/ExtractFunction.cpp
@@ -132,6 +132,7 @@
     // always unselected.
     return Parent->ASTNode.get<DeclStmt>() ? Parent->Parent : Parent;
   }
+  llvm_unreachable("Unhandled SelectionTree::Selection enum");
 }
 
 // The ExtractionZone class forms a view of the code wrt Zone.