diff --git a/pkgs/racket-pkgs/racket-test/tests/racket/port.rktl b/pkgs/racket-pkgs/racket-test/tests/racket/port.rktl
index 80b0b91c7a..1d69611d85 100644
--- a/pkgs/racket-pkgs/racket-test/tests/racket/port.rktl
+++ b/pkgs/racket-pkgs/racket-test/tests/racket/port.rktl
@@ -505,6 +505,19 @@
     (test #"12311-" values s))
   (test 3 write-bytes-avail #"1234" out))
 
+;; Further test of peeking in a limited pipe (shouldn't get stuck):
+(let-values ([(i o) (make-pipe 50)]
+             [(s) (make-semaphore)])
+  (define t
+    (thread (lambda ()
+              (peek-bytes 100 0 i)
+              (semaphore-wait s)
+              (peek-bytes 200 0 i))))
+  (display (make-bytes 100 65) o)
+  (sync (system-idle-evt))
+  (semaphore-post s)
+  (display (make-bytes 100 66) o)
+  (sync t))
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Provide a location proc:
diff --git a/racket/src/racket/src/portfun.c b/racket/src/racket/src/portfun.c
index 58aa8972e6..f6bd569c5b 100644
--- a/racket/src/racket/src/portfun.c
+++ b/racket/src/racket/src/portfun.c
@@ -1655,9 +1655,9 @@ int scheme_is_user_port(Scheme_Object *port)
 /*                               pipe ports                               */
 /*========================================================================*/
 
-static void pipe_did_read(Scheme_Input_Port *port, Scheme_Pipe *pipe)
+static void pipe_did_read(Scheme_Input_Port *port, Scheme_Pipe *pipe, int peek)
 {
-  if (port && port->progress_evt) {
+  if (port && port->progress_evt && !peek) {
     scheme_post_sema_all(port->progress_evt);
     port->progress_evt = NULL;
   }
@@ -1789,7 +1789,7 @@ static intptr_t pipe_get_or_peek_bytes(Scheme_Input_Port *p,
       else
 	pipe->bufmaxextra = 0;
     }
-    pipe_did_read(p, pipe);
+    pipe_did_read(p, pipe, 0);
   } else {
     if (!c) {
       if (size && pipe->eof)
@@ -1809,6 +1809,7 @@ static intptr_t pipe_get_or_peek_bytes(Scheme_Input_Port *p,
 	  pipe->bufmaxextra = c + skipped;
 	}
       }
+      pipe_did_read(p, pipe, 1);
     }
   }
 
@@ -1897,6 +1898,7 @@ static intptr_t pipe_write_bytes(Scheme_Output_Port *p,
       wrote += xavail;
       d += xavail;
       len -= xavail;
+      pipe_did_write(pipe);
 
       /* For non-blocking mode, that might be good enough.
 	 rarely_block == 2 means that even nothing is good enough. */
@@ -1904,34 +1906,33 @@ static intptr_t pipe_write_bytes(Scheme_Output_Port *p,
 	return wrote;
 
       /* Now, wait until we can write more, then start over. */
-      while (1) {
-	if (pipe->bufstart <= pipe->bufend) {
-	  avail = (pipe->buflen - pipe->bufend) + pipe->bufstart - 1;
-	} else {
-	  avail = pipe->bufstart - pipe->bufend - 1;
-	}
-	if (pipe->bufmax) {
-	  /* Again, it's possible that the port grew to accommodate
-	     past peeks... */
-	  intptr_t extra;
-	  extra = pipe->buflen - (pipe->bufmax + pipe->bufmaxextra);
-	  if (extra > 0)
-	    avail -= extra;
-	}
-
-	if (avail || pipe->eof || p->closed)
-	  goto try_again;
-
-	my_sema = scheme_make_sema(0);
-	{
-	  Scheme_Object *wp;
-	  wp = scheme_make_pair(my_sema, pipe->wakeup_on_read);
-	  pipe->wakeup_on_read = wp;
-	}
-
-	scheme_wait_sema(my_sema, enable_break ? -1 : 0);
+      if (pipe->bufstart <= pipe->bufend) {
+        avail = (pipe->buflen - pipe->bufend) + pipe->bufstart - 1;
+      } else {
+        avail = pipe->bufstart - pipe->bufend - 1;
       }
-      /* Doesn't get here */
+      if (pipe->bufmax) {
+        /* Again, it's possible that the port grew to accommodate
+           past peeks... */
+        intptr_t extra;
+        extra = pipe->buflen - (pipe->bufmax + pipe->bufmaxextra);
+        if (extra > 0)
+          avail -= extra;
+      }
+      
+      if (avail || pipe->eof || p->closed)
+        goto try_again;
+      
+      my_sema = scheme_make_sema(0);
+      {
+        Scheme_Object *wp;
+        wp = scheme_make_pair(my_sema, pipe->wakeup_on_read);
+        pipe->wakeup_on_read = wp;
+      }
+      
+      scheme_wait_sema(my_sema, enable_break ? -1 : 0);
+      
+      goto try_again;
     }
   }
 
@@ -1989,7 +1990,7 @@ static intptr_t pipe_write_bytes(Scheme_Output_Port *p,
   pipe->bufend = endpos;
 
   pipe_did_write(pipe);
-
+  
   return len + wrote;
 }
 
@@ -2014,7 +2015,7 @@ static void pipe_in_close(Scheme_Input_Port *p)
   pipe->eof = 1;
 
   /* to wake up any other threads blocked on pipe I/O: */
-  pipe_did_read(p, pipe);
+  pipe_did_read(p, pipe, 0);
   pipe_did_write(pipe);
 }
 
@@ -2027,7 +2028,7 @@ static void pipe_out_close(Scheme_Output_Port *p)
   pipe->eof = 1;
 
   /* to wake up any other threads blocked on pipe I/O: */
-  pipe_did_read(NULL, pipe);
+  pipe_did_read(NULL, pipe, 0);
   pipe_did_write(pipe);
 }