diff --git a/newlib/libc/include/sys/types.h b/newlib/libc/include/sys/types.h
index 31f765e3e..1d2d54c37 100644
--- a/newlib/libc/include/sys/types.h
+++ b/newlib/libc/include/sys/types.h
@@ -66,7 +66,12 @@ typedef	quad_t *	qaddr_t;
 #include <sys/select.h>
 #  define	physadr		physadr_t
 #  define	quad		quad_t
+
+#ifndef _IN_ADDR_T_DECLARED
+typedef	__uint32_t	in_addr_t;	/* base type for internet address */
+#define	_IN_ADDR_T_DECLARED
 #endif
+#endif /* __BSD_VISIBLE */
 
 #if __MISC_VISIBLE
 #ifndef _BSDTYPES_DEFINED
diff --git a/winsup/cygwin/include/cygwin/in.h b/winsup/cygwin/include/cygwin/in.h
index a64160e8f..3242d6878 100644
--- a/winsup/cygwin/include/cygwin/in.h
+++ b/winsup/cygwin/include/cygwin/in.h
@@ -20,8 +20,12 @@
 
 #include <cygwin/socket.h>
 
+#ifndef _IN_ADDR_T_DECLARED
+typedef	__uint32_t	in_addr_t;
+#define	_IN_ADDR_T_DECLARED
+#endif
+
 typedef uint16_t in_port_t;
-typedef uint32_t in_addr_t;
 
 #ifndef __INSIDE_CYGWIN_NET__