diff --git a/sh.py b/sh.py
index <HASH>..<HASH> 100644
--- a/sh.py
+++ b/sh.py
@@ -668,8 +668,10 @@ class Command(object):
         #("fg", "bg", "Command can't be run in the foreground and background"),
         ("err", "err_to_out", "Stderr is already being redirected"),
         ("piped", "iter", "You cannot iterate when this command is being piped"),
-        ("piped", "no_pipe", "Using a pipe doesn't make sense if you've\
+        ("piped", "no_pipe", "Using a pipe doesn't make sense if you've \
 disabled the pipe"),
+        ("no_out", "iter", "You cannot iterate over output if there is no \
+output"),
     )
added new incompatible args, closes #<I>