diff --git a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
index aa8b8fb..1d63e33 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp
@@ -130,6 +130,7 @@
 
 void DebugHandlerBase::beginFunction(const MachineFunction *MF) {
   assert(Asm);
+  PrevInstBB = nullptr;
 
   if (!hasDebugInfo(MMI, MF)) {
     skippedNonDebugFunction();