diff --git a/commands/hugo.go b/commands/hugo.go
index db30148d1..025398f4b 100644
--- a/commands/hugo.go
+++ b/commands/hugo.go
@@ -112,6 +112,7 @@ func init() {
 	// for Bash autocomplete
 	validConfigFilenames := []string{"json", "js", "yaml", "yml", "toml", "tml"}
 	HugoCmd.PersistentFlags().SetAnnotation("config", cobra.BashCompFilenameExt, validConfigFilenames)
+	HugoCmd.PersistentFlags().SetAnnotation("theme", cobra.BashCompSubdirsInDir, []string{"themes"})
 
 	// This message will be shown to Windows users if Hugo is opened from explorer.exe
 	cobra.MousetrapHelpText = `