diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 660e661698..676bd9de58 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -51,6 +51,7 @@
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/system_error.h"
 #include <algorithm>
+#include <cstdio>
 #include <iterator>
 
 using namespace clang;