diff --git a/src/options.rs b/src/options.rs
index 7b45b27..7431784 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -93,7 +93,7 @@ impl EngineOption {
   pub fn option_string(&self) -> String {
     let mut option_data_string: String = String::new();
 
-    for (ref dt, ref eod) in self.option_data {
+    for (dt, eod) in self.option_data.iter() {
       let dts = match *dt {
         EngineOptionDataType::DefaultVal => "default",
         EngineOptionDataType::Min => "min",
@@ -104,7 +104,7 @@ impl EngineOption {
       let res = match *eod {
         EngineOptionData::Int(v) => v.to_string(),
         EngineOptionData::Float(v) => v.to_string(),
-        EngineOptionData::Text(v) => v,
+        EngineOptionData::Text(ref v) => v.clone(),
       };
 
       option_data_string.push_str(&format!("{} {:?} ", dts, res));