diff --git a/include/llvm/Support/Signals.h b/include/llvm/Support/Signals.h
index 72bfd6b3389..465656b9411 100644
--- a/include/llvm/Support/Signals.h
+++ b/include/llvm/Support/Signals.h
@@ -16,6 +16,7 @@
 #define LLVM_SUPPORT_SIGNALS_H
 
 #include "llvm/Support/Path.h"
+#include <cstdio>
 
 namespace llvm {
 namespace sys {