diff --git a/include/Support/StringExtras.h b/include/Support/StringExtras.h
index ad7527b4696..fdf32272de8 100644
--- a/include/Support/StringExtras.h
+++ b/include/Support/StringExtras.h
@@ -16,8 +16,8 @@
 
 #include "Support/DataTypes.h"
 #include <cctype>
+#include <cstdio>
 #include <string>
-#include <stdio.h>
 
 namespace llvm {
 
diff --git a/include/llvm/ADT/StringExtras.h b/include/llvm/ADT/StringExtras.h
index ad7527b4696..fdf32272de8 100644
--- a/include/llvm/ADT/StringExtras.h
+++ b/include/llvm/ADT/StringExtras.h
@@ -16,8 +16,8 @@
 
 #include "Support/DataTypes.h"
 #include <cctype>
+#include <cstdio>
 #include <string>
-#include <stdio.h>
 
 namespace llvm {