diff --git a/src/doc/rustdoc/src/command-line-arguments.md b/src/doc/rustdoc/src/command-line-arguments.md
index 2e4016e24bc3f..c8af369a9695e 100644
--- a/src/doc/rustdoc/src/command-line-arguments.md
+++ b/src/doc/rustdoc/src/command-line-arguments.md
@@ -417,3 +417,10 @@ This flag is **deprecated** and **has no effect**.
 Rustdoc only supports Rust source code and Markdown input formats. If the
 file ends in `.md` or `.markdown`, `rustdoc` treats it as a Markdown file.
 Otherwise, it assumes that the input file is Rust.
+
+## `--nocapture`
+
+When this flag is used with `--test`, the output (stdout and stderr) of your tests won't be
+captured by rustdoc. Instead, the output will be directed to your terminal,
+as if you had run the test executable manually. This is especially useful
+for debugging your tests!