diff --git a/runtime/Cpp/runtime/src/ANTLRInputStream.cpp b/runtime/Cpp/runtime/src/ANTLRInputStream.cpp
index 889492ace..1ef8fd4d1 100755
--- a/runtime/Cpp/runtime/src/ANTLRInputStream.cpp
+++ b/runtime/Cpp/runtime/src/ANTLRInputStream.cpp
@@ -3,6 +3,8 @@
  * can be found in the LICENSE.txt file in the project root.
  */
 
+#include <string.h>
+
 #include "Exceptions.h"
 #include "misc/Interval.h"
 #include "IntStream.h"