diff --git a/src/bin.rs b/src/bin.rs
index bf6445c..35aa36b 100644
--- a/src/bin.rs
+++ b/src/bin.rs
@@ -108,7 +108,7 @@ fn print_t_test(t_test: &TTest, s1: &Summary, s2: &Summary) {
     println!("{l:>w$} = {v}", w = width, l = "DF", v = t_test.df);
 }
 
-fn summarize_file(path: &str, lax_parsing: bool) -> Result<Summary, Box<error::Error>> {
+fn summarize_file(path: &str, lax_parsing: bool) -> Result<Summary, Box<dyn error::Error>> {
     let f = File::open(path).or_else(|e| {
         log::error(&format!("Could not open file: {:?}", path));
         Err(e)
@@ -120,7 +120,7 @@ fn summarize_file(path: &str, lax_parsing: bool) -> Result<Summary, Box<error::E
     Ok(Summary::new(&data)?)
 }
 
-fn read_data<R>(reader: R, lax_parsing: bool) -> Result<Vec<f64>, Box<error::Error>>
+fn read_data<R>(reader: R, lax_parsing: bool) -> Result<Vec<f64>, Box<dyn error::Error>>
     where R: BufRead {
     let mut data: Vec<f64> = vec![];
 
@@ -140,7 +140,7 @@ fn read_data<R>(reader: R, lax_parsing: bool) -> Result<Vec<f64>, Box<error::Err
     Ok(data)
 }
 
-fn summarize_stdin(lax_parsing: bool) -> Result<Summary, Box<error::Error>> {
+fn summarize_stdin(lax_parsing: bool) -> Result<Summary, Box<dyn error::Error>> {
     let stdin = io::stdin();
     let data = read_data(stdin.lock(), lax_parsing)?;
 
diff --git a/src/error.rs b/src/error.rs
index cb8a751..002f330 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -11,17 +11,17 @@ pub enum Error {
 
 impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
-        write!(f, "{}", std::error::Error::description(self))
+        write!(
+            f,
+            "{}",
+            match *self {
+                Error::BadSample => "All sample data must be finite",
+                Error::Diverged => "Numeric evaluation diverged",
+                Error::EmptySample => "Sample data set cannot be empty",
+                Error::Undefined => "Function undefined for argument",
+            }
+        )
     }
 }
 
-impl std::error::Error for Error {
-    fn description(&self) -> &str {
-        match *self {
-            Error::BadSample => "All sample data must be finite",
-            Error::Diverged => "Numeric evaluation diverged",
-            Error::EmptySample => "Sample data set cannot be empty",
-            Error::Undefined => "Function undefined for argument",
-        }
-    }
-}
+impl std::error::Error for Error {}
diff --git a/tests/support/kat.rs b/tests/support/kat.rs
index 89ac66e..b92bbe6 100644
--- a/tests/support/kat.rs
+++ b/tests/support/kat.rs
@@ -157,10 +157,8 @@ macro_rules! assert_appx_eq {
     ($name:expr, $tolerance:expr, $known:expr, $actual:expr) => {
         let d = ($known - $actual).abs();
 
-        let err = format!("{}: {} and {} differ by {} > {}",
-                          $name, $known, $actual, d, $tolerance);
-
-        assert!(d < $tolerance, err);
+        assert!(d < $tolerance, "{}: {} and {} differ by {} > {}",
+                $name, $known, $actual, d, $tolerance);
     };
 }