diff --git a/Cargo.toml b/Cargo.toml
index 5baa8a6..7222314 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,11 +9,15 @@ edition = "2018"
 [dependencies]
 # Logger
 log = "0.4"
-simplelog = "0.7"
+simplelog = "0.8"
 # Struct serializing and deserializing
 serde = {version = "1.0", features = ["derive"]}
-serde_yaml = "0.7"
+serde_yaml = "0.8"
 serde_json = "1.0"
 # Regex support
 regex = "1.3"
-lazy_static = "1.4.0"
+lazy_static = "1.4"
+
+# [dev-dependencies]
+# Pretty output
+prettydiff = "0.3"
diff --git a/src/lib.rs b/src/lib.rs
index 5b1f9d8..37535e7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,12 +12,8 @@
 //! [original software](https://github.com/ceronyon/LangEvolve) which applies
 //! user-defined sound changes to words and texts based on regex expressions.
 
-#[macro_use]
-extern crate lazy_static;
-
 use std::fs::File;
-extern crate log;
-extern crate simplelog;
+
 use log::{info, warn};
 use simplelog::*;
 
diff --git a/src/settings/mod.rs b/src/settings/mod.rs
index 40f839b..8315305 100644
--- a/src/settings/mod.rs
+++ b/src/settings/mod.rs
@@ -1,13 +1,11 @@
-extern crate serde;
-extern crate serde_json;
-extern crate serde_yaml;
 use serde::{Deserialize, Serialize};
 
-extern crate log;
 use log::{debug, error, info};
 
 use crate::utils::{self, SettingsType};
 
+use prettydiff::diff_words;
+
 mod rule;
 use rule::Rule;
 
diff --git a/src/settings/rule/mod.rs b/src/settings/rule/mod.rs
index a233fb5..3563945 100644
--- a/src/settings/rule/mod.rs
+++ b/src/settings/rule/mod.rs
@@ -1,13 +1,16 @@
 use std::collections::HashMap;
 
-extern crate serde;
-extern crate serde_json;
-extern crate serde_yaml;
 use serde::{Deserialize, Serialize};
 
+use lazy_static::lazy_static;
+
 mod regex_wrapper;
 use regex_wrapper::Regex;
 
+lazy_static! {
+    static ref RE : Regex = Regex::new("%([A-Z])");
+}
+
 /// Representation of a rule in LangEvolveRs
 #[derive(Debug, Serialize, Deserialize, Clone)]
 pub struct Rule {
@@ -34,9 +37,6 @@ impl Rule {
     }
 
     fn detect_categories(&self) -> (u8, u8) {
-        lazy_static! {
-            static ref RE : Regex = Regex::new("%([A-Z])");
-        }
         let captures_from = match RE.captures(self.from.as_str()) {
             None => 0 as u8,
             Some(c) => c.len() as u8,
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 184f47b..5ef64cf 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -1,4 +1,3 @@
-extern crate log;
 use log::{info, error};
 
 use std::fs::File;