diff --git a/llvm/lib/BinaryFormat/XCOFF.cpp b/llvm/lib/BinaryFormat/XCOFF.cpp
index 6613b63..001b807 100644
--- a/llvm/lib/BinaryFormat/XCOFF.cpp
+++ b/llvm/lib/BinaryFormat/XCOFF.cpp
@@ -22,6 +22,8 @@
     return "TC0";
   case XCOFF::XMC_BS:
     return "BS";
+  case XCOFF::XMC_RO:
+    return "RO";
   default:
     report_fatal_error("Unhandled storage-mapping class.");
   }