diff --git a/lib/MC/MCObjectFileInfo.cpp b/lib/MC/MCObjectFileInfo.cpp
index d42231264da..b88d2d80182 100644
--- a/lib/MC/MCObjectFileInfo.cpp
+++ b/lib/MC/MCObjectFileInfo.cpp
@@ -962,6 +962,7 @@ MCSection *MCObjectFileInfo::getDwarfTypesSection(uint64_t Hash) const {
                        "format: not implemented.");
     break;
   }
+  llvm_unreachable("Unknown ObjectFormatType");
 }
 
 MCSection *