diff --git a/lib/poll.c b/lib/poll.c
index 90d99d9..024ffa9 100644
--- a/lib/poll.c
+++ b/lib/poll.c
@@ -35,7 +35,9 @@
 
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
 # define WIN32_NATIVE
-# include <winsock2.h>
+# define _GL_INCLUDING_WINSOCK2_H
+#  include <winsock2.h>
+# undef _GL_INCLUDING_WINSOCK2_H
 # include <windows.h>
 # include <io.h>
 # include <stdio.h>
diff --git a/lib/select.c b/lib/select.c
index 3564566..66468bf 100644
--- a/lib/select.c
+++ b/lib/select.c
@@ -31,7 +31,9 @@
 #include <errno.h>
 #include <limits.h>
 
-#include <winsock2.h>
+#define _GL_INCLUDING_WINSOCK2_H
+# include <winsock2.h>
+#undef _GL_INCLUDING_WINSOCK2_H
 #include <windows.h>
 #include <io.h>
 #include <stdio.h>
diff --git a/lib/strerror.c b/lib/strerror.c
index b0df778..c13aa1c 100644
--- a/lib/strerror.c
+++ b/lib/strerror.c
@@ -26,7 +26,9 @@
 
 # if GNULIB_defined_ESOCK /* native Windows platforms */
 #  if HAVE_WINSOCK2_H
-#   include <winsock2.h>
+#   define _GL_INCLUDING_WINSOCK2_H
+#    include <winsock2.h>
+#   undef _GL_INCLUDING_WINSOCK2_H
 #  endif
 # endif
 
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 7c7ecd8..13bdda5 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -31,7 +31,7 @@
    that <winsock2.h> is completely included first.  */
 #if @GNULIB_GETHOSTNAME@
 /* Get all possible declarations of gethostname().  */
-# if @UNISTD_H_HAVE_WINSOCK2_H@
+# if @UNISTD_H_HAVE_WINSOCK2_H@ && !defined _GL_INCLUDING_WINSOCK2_H
 #  define _GL_INCLUDING_WINSOCK2_H
 #  include <winsock2.h>
 #  undef _GL_INCLUDING_WINSOCK2_H