diff --git a/lib/System/Path.cpp b/lib/System/Path.cpp
index d58275944c5..a530f28273f 100644
--- a/lib/System/Path.cpp
+++ b/lib/System/Path.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/System/Path.h"
+#include <cassert>
 
 namespace llvm {
 using namespace sys;