diff --git a/TODO.FACTOR.txt b/TODO.FACTOR.txt
index 76853b736e..f138c7ebb6 100644
--- a/TODO.FACTOR.txt
+++ b/TODO.FACTOR.txt
@@ -9,7 +9,6 @@
 - get all-tests to run with -no-compile
 - if external factor is down, don't add tons of random shit to the dictionary
 - scalar * matrix, vector * matrix, matrix * vector need to work
-- turning vectors into row and column matrices
 - make-matrix is slow and ugly
 - move 2repeat somewhere else
 - rotating cube demo
diff --git a/library/threads.factor b/library/threads.factor
index 7c2e496c13..86fb457043 100644
--- a/library/threads.factor
+++ b/library/threads.factor
@@ -19,13 +19,13 @@ namespaces ;
         deque set-run-queue
     ] ifte ;
 
-: schedule-thread ( quot -- ) run-queue enque set-run-queue ;
+: schedule-thread ( quot -- )
+    run-queue enque set-run-queue ;
 
 : stop ( -- )
-    #! If there is a quotation in the run queue, call it,
-    #! otherwise wait for I/O.
-    pending-io? [ 10 io-multiplex ] when
-    next-thread [ call ] [ -1 io-multiplex stop ] ifte* ;
+    ! This definition gets replaced by the Unix and Win32 I/O
+    ! code.
+    next-thread [ call ] [ "No more tasks" throw ] ifte* ;
 
 : yield ( -- )
     #! Add the current continuation to the run queue, and yield
diff --git a/library/unix/io.factor b/library/unix/io.factor
index 9685cc5cbd..6d528b80e7 100644
--- a/library/unix/io.factor
+++ b/library/unix/io.factor
@@ -388,3 +388,11 @@ USE: stdio
 IN: streams
 
 : fcopy 2drop ;
+
+IN: threads
+
+: stop ( -- )
+    #! If there is a quotation in the run queue, call it,
+    #! otherwise wait for I/O.
+    pending-io? [ 10 io-multiplex ] when
+    next-thread [ call ] [ -1 io-multiplex stop ] ifte* ;