diff --git a/runtime/doc/vim.1 b/runtime/doc/vim.1
index d78bf2e..69c6d30 100644
--- a/runtime/doc/vim.1
+++ b/runtime/doc/vim.1
@@ -314,6 +314,10 @@
 Open N windows side by side.
 When N is omitted, open one window for each file.
 .TP
+\-p[N]
+Open N tab pages.
+When N is omitted, open one tab page for each file.
+.TP
 \-R
 Read-only mode.
 The 'readonly' option will be set.