diff --git a/mlir/include/mlir/Dialect/SCF/IR/SCF.h b/mlir/include/mlir/Dialect/SCF/IR/SCF.h
--- a/mlir/include/mlir/Dialect/SCF/IR/SCF.h
+++ b/mlir/include/mlir/Dialect/SCF/IR/SCF.h
@@ -63,7 +63,11 @@
 using ValueVector = std::vector<Value>;
 using LoopVector = std::vector<scf::ForOp>;
 struct LoopNest {
-  ResultRange getResults() { return loops.front().getResults(); }
+  ValueRange getResults() {
+    if (loops.empty())
+      return llvm::None;
+    return loops.front().getResults();
+  }
   LoopVector loops;
 };