diff --git a/collects/tests/racket/port.rktl b/collects/tests/racket/port.rktl
index 94e37bbe43..0dbf29f7db 100644
--- a/collects/tests/racket/port.rktl
+++ b/collects/tests/racket/port.rktl
@@ -394,14 +394,17 @@
 			    (- end start))))
    (lambda (special) always-evt)))
 (test (void) display "hello" /dev/null-out)
+(set! should-be-breakable? #f)
 (test 5 write-bytes-avail #"hello" /dev/null-out)
+(set! should-be-breakable? #t)
 (test #t write-special 'hello /dev/null-out)
 (test 5 sync (write-bytes-avail-evt #"hello" /dev/null-out))
+(set! should-be-breakable? #f)
 (test 5 write-bytes-avail/enable-break #"hello" /dev/null-out)
 (test #t write-special-avail* 'hello /dev/null-out)
 (parameterize-break #f
-  (test 5 write-bytes-avail/enable-break #"hello" /dev/null-out)
   (set! should-be-breakable? #f)
+  (test 5 write-bytes-avail/enable-break #"hello" /dev/null-out)
   (test #t write-special-avail* 'hello /dev/null-out)
   (test 5 write-bytes-avail #"hello" /dev/null-out))
 
@@ -639,6 +642,34 @@
    #f 
    (try (lambda (x) (read-bytes-avail!/enable-break (make-bytes 10) x)))))
 
+;; Check nonblock? and break? interaction (again):
+(let ()
+  (define status '())
+  (define p (make-output-port
+             'p
+             always-evt
+             (lambda (bstr start end nonblock? break?)
+               (set! status (list nonblock? break? (break-enabled)))
+               (- end start))
+             void
+             (lambda (v nonblock? break?)
+               (set! status (list 'special nonblock? break? (break-enabled)))
+               #t)))
+  (write-bytes #"hi" p)
+  (test '(#f #t #f) values status)
+  (parameterize-break
+   #f
+   (write-bytes #"hi" p))
+  (test '(#f #f #f) values status)
+  (write-bytes-avail #"hi" p)
+  (test '(#t #f #f) values status)
+  (write-bytes-avail* #"hi" p)
+  (test '(#t #f #f) values status)
+  (write-special 'any p)
+  (test '(special #f #t #f) values status)
+  (write-special-avail* 'any p)
+  (test '(special #t #f #f) values status))
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Check that an uncooperative output port doesn't keep breaks
 ;; disabled too long:
diff --git a/src/racket/src/portfun.c b/src/racket/src/portfun.c
index 247de7926b..f961947372 100644
--- a/src/racket/src/portfun.c
+++ b/src/racket/src/portfun.c
@@ -1375,7 +1375,9 @@ user_write_bytes(Scheme_Output_Port *port, const char *str, intptr_t offset, int
   int n, re_enable_break;
   Scheme_Cont_Frame_Data cframe;
 
-  if (enable_break)
+  if (rarely_block)
+    re_enable_break = 0;
+  else if (enable_break)
     re_enable_break = 1;
   else
     re_enable_break = scheme_can_break(scheme_current_thread);
@@ -1512,7 +1514,10 @@ user_write_special (Scheme_Output_Port *port, Scheme_Object *v, int nonblock)
   int re_enable_break;
   Scheme_Cont_Frame_Data cframe;
 
-  re_enable_break = scheme_can_break(scheme_current_thread);
+  if (nonblock)
+    re_enable_break = 0;
+  else
+    re_enable_break = scheme_can_break(scheme_current_thread);
 
   a[0] = v;
   a[1] = (nonblock ? scheme_true : scheme_false);