diff --git a/libguile/ChangeLog b/libguile/ChangeLog
index 8371560ff..fac10cb77 100644
--- a/libguile/ChangeLog
+++ b/libguile/ChangeLog
@@ -1,3 +1,7 @@
+2001-03-13  Martin Grabmueller  <mgrabmue@cs.tu-berlin.de>
+
+	* ports.c (scm_port_mode): Changed `mode' array size to 4.
+
 2001-03-12  Keisuke Nishida  <kxn30@po.cwru.edu>
 
 	* strports.c (scm_object_to_string): New procedure.
diff --git a/libguile/ports.c b/libguile/ports.c
index e8c739b30..e18dff08f 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -609,7 +609,7 @@ SCM_DEFINE (scm_port_mode, "port-mode", 1, 0, 0,
 	    "port creation are not retained.")
 #define FUNC_NAME s_scm_port_mode
 {
-  char modes[3];
+  char modes[4];
   modes[0] = '\0';
 
   port = SCM_COERCE_OUTPORT (port);