diff --git a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -577,10 +577,12 @@
 }
 
 void DWARFUnit::clearDIEs(bool KeepCUDie) {
-  if (DieArray.size() > (unsigned)KeepCUDie) {
-    DieArray.resize((unsigned)KeepCUDie);
-    DieArray.shrink_to_fit();
-  }
+  if (KeepCUDie && DieArray.size() > 0) {
+    std::vector<DWARFDebugInfoEntry> VectorWithSingleCU(1);
+    VectorWithSingleCU.emplace_back(DieArray[0]);
+    DieArray = VectorWithSingleCU;
+  } else
+    DieArray = std::vector<DWARFDebugInfoEntry>(0);
 }
 
 Expected<DWARFAddressRangesVector>