diff --git a/src/command.rs b/src/command.rs
index 55cbb5e74..fac3f5440 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -62,7 +62,7 @@ impl<'a> Command<'a> {
         let parameters =
             self.get_unused_parameters()
                 .fold(String::new(), |output, (parameter, value)| {
-                    output + &format!("{} = {}, ", parameter, value.to_string())
+                    output + &format!("{} = {}, ", parameter, value)
                 });
         let parameters = parameters.trim_end_matches(", ");
         let parameters = if parameters.is_empty() {
diff --git a/src/parameter/mod.rs b/src/parameter/mod.rs
index 994f4a2fd..5f1e1943c 100644
--- a/src/parameter/mod.rs
+++ b/src/parameter/mod.rs
@@ -1,3 +1,4 @@
+use std::fmt::Display;
 use crate::util::number::Number;
 
 pub mod range_step;
@@ -9,12 +10,13 @@ pub enum ParameterValue {
     Numeric(Number),
 }
 
-impl ToString for ParameterValue {
-    fn to_string(&self) -> String {
-        match self {
+impl Display for ParameterValue {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let str = match self {
             ParameterValue::Text(ref value) => value.clone(),
             ParameterValue::Numeric(value) => value.to_string(),
-        }
+        };
+        write!(f, "{}", str)
     }
 }
 
diff --git a/src/util/min_max.rs b/src/util/min_max.rs
index 9e11f5550..de5074cd3 100644
--- a/src/util/min_max.rs
+++ b/src/util/min_max.rs
@@ -1,4 +1,3 @@
-use std::iter::Iterator;
 
 /// A max function for f64's without NaNs
 pub fn max(vals: &[f64]) -> f64 {