diff --git a/cmd/optimize_command.go b/cmd/optimize_command.go
index 05210fb..6b7243e 100644
--- a/cmd/optimize_command.go
+++ b/cmd/optimize_command.go
@@ -49,7 +49,7 @@ func ConvertCbzCommand(cmd *cobra.Command, args []string) error {
 	}
 
 	quality, err := cmd.Flags().GetUint8("quality")
-	if err != nil {
+	if err != nil || quality <= 0 || quality > 100 {
 		return fmt.Errorf("invalid quality value")
 	}
 
diff --git a/cmd/watch_command.go b/cmd/watch_command.go
index 2283a04..e93a511 100644
--- a/cmd/watch_command.go
+++ b/cmd/watch_command.go
@@ -55,7 +55,7 @@ func WatchCommand(_ *cobra.Command, args []string) error {
 	}
 
 	quality := uint8(viper.GetUint16("quality"))
-	if quality <= 0 {
+	if quality <= 0 || quality > 100 {
 		return fmt.Errorf("invalid quality value")
 	}