diff --git a/src/doc/rustc/src/command-line-arguments.md b/src/doc/rustc/src/command-line-arguments.md
index d7e789b5a11f7..dfb40284ef6cf 100644
--- a/src/doc/rustc/src/command-line-arguments.md
+++ b/src/doc/rustc/src/command-line-arguments.md
@@ -86,6 +86,13 @@ This flag will set which lints should be set to the [deny level](lints/levels.ht
 
 This flag will set which lints should be set to the [forbid level](lints/levels.html#forbid).
 
+## `-Z`: set unstable options
+
+This flag will allow you to set unstable options of rustc. In order to set multiple options,
+the -Z flag can be used multiple times. For example: `rustc -Z verbose -Z time`.
+Specifying options with -Z is only available on nightly. To view all available options
+run: `rustc -Z help`.
+
 ## `--cap-lints`: set the most restrictive lint level
 
 This flag lets you 'cap' lints, for more, [see here](lints/levels.html#capping-lints).
diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 4b7cffaad5509..ca6bd9616536e 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -743,7 +743,7 @@ fn usage(verbose: bool, include_unstable_options: bool) {
     }
     let message = "Usage: rustc [OPTIONS] INPUT";
     let nightly_help = if nightly_options::is_nightly_build() {
-        "\n    -Z help             Print internal options for debugging rustc"
+        "\n    -Z help             Print unstable compiler options"
     } else {
         ""
     };
@@ -891,7 +891,7 @@ Available lint options:
 }
 
 fn describe_debug_flags() {
-    println!("\nAvailable debug options:\n");
+    println!("\nAvailable options:\n");
     print_flag_list("-Z", config::DB_OPTIONS);
 }