diff --git a/flang/include/flang/Optimizer/Builder/HLFIRTools.h b/flang/include/flang/Optimizer/Builder/HLFIRTools.h
index 69874719572186..f073f494b3fb21 100644
--- a/flang/include/flang/Optimizer/Builder/HLFIRTools.h
+++ b/flang/include/flang/Optimizer/Builder/HLFIRTools.h
@@ -357,8 +357,8 @@ hlfir::ElementalOp genElementalOp(
 
 /// Structure to describe a loop nest.
 struct LoopNest {
-  mlir::Operation *outerOp;
-  mlir::Block *body;
+  mlir::Operation *outerOp = nullptr;
+  mlir::Block *body = nullptr;
   llvm::SmallVector<mlir::Value> oneBasedIndices;
 };