--- a/libguile/iselect.h
+++ b/libguile/iselect.h
@@ -29,7 +29,11 @@
 /* Needed for FD_SET on some systems.  */
 #include <sys/types.h>
 
+#ifdef __MINGW32__
+#include <winsock2.h>
+#else
 #include <sys/select.h>
+#endif
 
 SCM_API int scm_std_select (int fds,