diff --git a/README.md b/README.md
index 243c3acbc..4a6a7f600 100644
--- a/README.md
+++ b/README.md
@@ -563,9 +563,9 @@ The `<...>` notation means the argument.
 * `u[ntil]`
   * Similar to `next` command, but only stop later lines or the end of the current frame.
   * Similar to gdb's `advance` command.
-* `u[ntil] <[file:]line>
+* `u[ntil] <[file:]line>`
   * Run til the program reaches given location or the end of the current frame.
-* `u[ntil] <name>
+* `u[ntil] <name>`
   * Run til the program invokes a method `<name>`. `<name>` can be a regexp with `/name/`.
 * `c` or `cont` or `continue`
   * Resume the program.
diff --git a/lib/debug/session.rb b/lib/debug/session.rb
index 1402d554a..78bcce0de 100644
--- a/lib/debug/session.rb
+++ b/lib/debug/session.rb
@@ -480,9 +480,9 @@ def register_default_command
       # * `u[ntil]`
       #   * Similar to `next` command, but only stop later lines or the end of the current frame.
       #   * Similar to gdb's `advance` command.
-      # * `u[ntil] <[file:]line>
+      # * `u[ntil] <[file:]line>`
       #   * Run til the program reaches given location or the end of the current frame.
-      # * `u[ntil] <name>
+      # * `u[ntil] <name>`
       #   * Run til the program invokes a method `<name>`. `<name>` can be a regexp with `/name/`.
       register_command 'u', 'until',
                        repeat: true,