diff --git a/src/lib.rs b/src/lib.rs
index f35c913..edf1b99 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -155,6 +155,7 @@
 */
 
 #![deny(missing_docs)]
+#![warn(missing_debug_implementations)]
 #![forbid(unsafe_code)]
 
 pub use error::{Error, Result};
diff --git a/src/utf8.rs b/src/utf8.rs
index 489729e..89862af 100644
--- a/src/utf8.rs
+++ b/src/utf8.rs
@@ -84,6 +84,7 @@
 
 use std::char;
 use std::fmt;
+use std::iter::FusedIterator;
 use std::slice;
 
 const MAX_UTF8_BYTES: usize = 4;
@@ -295,6 +296,7 @@
 /// illustrative. In practice, you could just try to decode your byte sequence
 /// and compare it with the scalar value range directly. However, this is not
 /// always possible (for example, in a byte based automaton).
+#[derive(Debug)]
 pub struct Utf8Sequences {
     range_stack: Vec<ScalarRange>,
 }
@@ -388,6 +390,8 @@
     }
 }
 
+impl FusedIterator for Utf8Sequences {}
+
 impl ScalarRange {
     /// split splits this range if it overlaps with a surrogate codepoint.
     ///