diff --git a/Lib/ocaml/ocaml.swg b/Lib/ocaml/ocaml.swg
index e1d4a530f..70c15b526 100644
--- a/Lib/ocaml/ocaml.swg
+++ b/Lib/ocaml/ocaml.swg
@@ -2,6 +2,7 @@
 
 /* SWIG pointer structure */
 
+#include <string.h>
 #include <assert.h>
 
 #ifdef __cplusplus