diff --git a/.github/workflows/shaka-bot-commands/command-help.sh b/.github/workflows/shaka-bot-commands/command-help.sh
index 0a6e423429..864727ceea 100644
--- a/.github/workflows/shaka-bot-commands/command-help.sh
+++ b/.github/workflows/shaka-bot-commands/command-help.sh
@@ -24,4 +24,6 @@
   echo 'I honor the following commands from maintainers only:'
   echo ' - `@shaka-bot test`: Start lab tests on all devices'
   echo ' - `@shaka-bot test ce`: Start lab tests on CE devices only (no desktop browsers)'
+  echo ' - `@shaka-bot test cast`: Start lab tests on Cast devices only'
+  echo ' - `@shaka-bot test tizen`: Start lab tests on Tizen device only'
 ) | reply_from_pipe
diff --git a/.github/workflows/shaka-bot-commands/command-test.sh b/.github/workflows/shaka-bot-commands/command-test.sh
index fd92460dbe..03a6fc11f9 100644
--- a/.github/workflows/shaka-bot-commands/command-test.sh
+++ b/.github/workflows/shaka-bot-commands/command-test.sh
@@ -27,6 +27,12 @@ case "${SHAKA_BOT_ARGUMENTS[0]}" in
   # CE devices only.
   ce) WORKFLOW_ARGS+=( "browser_filter=Tizen ChromecastUltra ChromecastGTV ChromeAndroid" ) ;;
 
+  # Cast devices only.
+  cast) WORKFLOW_ARGS+=( "browser_filter=ChromecastUltra ChromecastGTV" ) ;;
+
+  # Tizen device only.
+  tizen) WORKFLOW_ARGS+=( "browser_filter=Tizen" ) ;;
+
   # No command argument, no extra workflow arguments.
   "") ;;