diff --git a/llvm/lib/MC/XCOFFObjectWriter.cpp b/llvm/lib/MC/XCOFFObjectWriter.cpp
--- a/llvm/lib/MC/XCOFFObjectWriter.cpp
+++ b/llvm/lib/MC/XCOFFObjectWriter.cpp
@@ -99,7 +99,7 @@
 // stored separately, e.g. the .data section containing read-write, descriptor,
 // TOCBase and TOC-entry csects.
 struct Section {
-  char Name[XCOFF::NameSize];
+  char Name[XCOFF::NameSize + 1];
   // The physical/virtual address of the section. For an object file
   // these values are equivalent.
   uint32_t Address;