diff --git a/libguile/win32-socket.c b/libguile/win32-socket.c
index a2556b6d1..959b4983d 100644
--- a/libguile/win32-socket.c
+++ b/libguile/win32-socket.c
@@ -42,6 +42,10 @@
 
 
 
+#if HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
 #include "libguile/__scm.h"
 #include "libguile/modules.h"
 #include "libguile/numbers.h"