diff --git a/skeletons/constr_CHOICE.c b/skeletons/constr_CHOICE.c
index d1beff4..7870a4c 100644
--- a/skeletons/constr_CHOICE.c
+++ b/skeletons/constr_CHOICE.c
@@ -3,7 +3,6 @@
  * Redistribution and modifications are permitted subject to BSD license.
  */
 #include <constr_CHOICE.h>
-#include <netinet/in.h>	/* for ntohl */
 #include <assert.h>
 
 /*
diff --git a/skeletons/constr_SET.c b/skeletons/constr_SET.c
index a01b804..2fd0ac9 100644
--- a/skeletons/constr_SET.c
+++ b/skeletons/constr_SET.c
@@ -3,9 +3,14 @@
  * Redistribution and modifications are permitted subject to BSD license.
  */
 #include <constr_SET.h>
-#include <netinet/in.h>	/* for ntohl() */
 #include <assert.h>	/* for assert() */
 
+#ifndef	WIN32
+#include <netinet/in.h>	/* for ntohl() */
+#else
+#include <winsock2.h>	/* for ntohl() */
+#endif
+
 /*
  * Number of bytes left for this structure.
  * (ctx->left) indicates the number of bytes _transferred_ for the structure.