diff --git a/include/llvm/Support/CommandLine.h b/include/llvm/Support/CommandLine.h
index 059c2a7ae11..515c18ed1d9 100644
--- a/include/llvm/Support/CommandLine.h
+++ b/include/llvm/Support/CommandLine.h
@@ -31,6 +31,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ManagedStatic.h"
 #include <cassert>
+#include <climits>
 #include <cstddef>
 #include <initializer_list>
 #include <string>