diff --git a/Library/Homebrew/dev-cmd/tests.rb b/Library/Homebrew/dev-cmd/tests.rb
index 05bdda8d2e..9d93fc9e86 100644
--- a/Library/Homebrew/dev-cmd/tests.rb
+++ b/Library/Homebrew/dev-cmd/tests.rb
@@ -1,4 +1,4 @@
-#:  * `tests` [`-v`] [`--coverage`] [`--generic`] [`--no-compat`] [`--only=`<test_script/test_method>] [`--seed` <seed>] [`--trace`] [`--online`] [`--official-cmd-taps`]:
+#:  * `tests` [`-v`] [`--coverage`] [`--generic`] [`--no-compat`] [`--only=`<test_script:test_method>] [`--seed` <seed>] [`--trace`] [`--online`] [`--official-cmd-taps`]:
 #:    Run Homebrew's unit and integration tests.
 
 require "fileutils"
diff --git a/completions/zsh/_brew b/completions/zsh/_brew
index 2d8e1b42be..9f7b8ebe52 100644
--- a/completions/zsh/_brew
+++ b/completions/zsh/_brew
@@ -678,7 +678,7 @@ _brew_test_bot() {
 }
 
 # brew tests [-v] [--coverage] [--generic] [--no-compat]
-#   [--only=test_script/test_method] [--seed seed] [--trace] [--online]
+#   [--only=test_script:test_method] [--seed seed] [--trace] [--online]
 #   [--official-cmd-taps]:
 _brew_tests() {
   _arguments \