1 files changed, 3 insertions, 0 deletions
diff --git a/toc/toc.1 b/toc/toc.1
index dbee298..413a206 100644
--- a/toc/toc.1
+++ b/toc/toc.1
@@ -19,6 +19,9 @@ from the end of the document to the beginning.
 As arguments, it takes a
 .Xr troff 1
 command line, which is evaluated as a shell command on each pass.
+If the command line is a pipeline,
+.Xr troff 1
+must be the final command.
 .Pp
 .Nm
 runs