diff --git a/libguile/ports.h b/libguile/ports.h
index 1756abaee..5c42ee70f 100644
--- a/libguile/ports.h
+++ b/libguile/ports.h
@@ -43,12 +43,14 @@
  * whether to permit this exception to apply to your modifications.
  * If you do not wish that, delete this exception notice.  */
 
-
 #include "libguile/__scm.h"
 
 #include "libguile/print.h"
 #include "libguile/struct.h"
 
+/* Not sure if this is a good idea.  We need it for off_t.  */
+#include <sys/types.h>
+
 
 
 #define SCM_INITIAL_CBUF_SIZE 4