diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 91f62b8..2b432c0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -591,7 +591,7 @@
         // 2.17.3).
         U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
       } else {
-        RangeSpan &Range = TheCU.getRanges().back();
+        const RangeSpan &Range = TheCU.getRanges().back();
         U.attachLowHighPC(U.getUnitDie(), Range.getStart(), Range.getEnd());
       }
     }