diff --git a/include/llvm/Metadata.h b/include/llvm/Metadata.h
index 001bfca9616..aef40bf11b7 100644
--- a/include/llvm/Metadata.h
+++ b/include/llvm/Metadata.h
@@ -23,7 +23,6 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/ilist_node.h"
 #include "llvm/Support/ErrorHandling.h"