diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index 6aa347d..25f02b9 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -399,7 +399,7 @@
   }
   for (const auto &Arg : DebugPrefixMap) {
     const auto &KV = StringRef(Arg).split('=');
-    Ctx.addDebugPrefixMapEntry(KV.first, KV.second);
+    Ctx.addDebugPrefixMapEntry(std::string(KV.first), std::string(KV.second));
   }
   if (!MainFileName.empty())
     Ctx.setMainFileName(MainFileName);