diff --git a/llvm/tools/llvm-ar/Archive.h b/llvm/tools/llvm-ar/Archive.h
index 232a5c23d2a4..6c7575a87d69 100644
--- a/llvm/tools/llvm-ar/Archive.h
+++ b/llvm/tools/llvm-ar/Archive.h
@@ -23,6 +23,7 @@
 #include "llvm/Support/TimeValue.h"
 #include <map>
 #include <set>
+#include <vector.h>
 
 namespace llvm {
   class MemoryBuffer;