diff --git a/src/lowercase/mod.rs b/src/lowercase/mod.rs
index e87b43820..1d5c87d93 100644
--- a/src/lowercase/mod.rs
+++ b/src/lowercase/mod.rs
@@ -27,6 +27,12 @@ pub struct Lowercase<'a> {
     iter: Inner<'a>,
 }
 
+impl<'a> Default for Lowercase<'a> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'a> Lowercase<'a> {
     /// Create a new, empty lowercase iterator.
     ///
diff --git a/src/titlecase/mod.rs b/src/titlecase/mod.rs
index bd3d450c5..f24c061d0 100644
--- a/src/titlecase/mod.rs
+++ b/src/titlecase/mod.rs
@@ -27,6 +27,12 @@ pub struct Titlecase<'a> {
     iter: Inner<'a>,
 }
 
+impl<'a> Default for Titlecase<'a> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'a> Titlecase<'a> {
     /// Create a new, empty titlecase iterator.
     ///
diff --git a/src/uppercase/mod.rs b/src/uppercase/mod.rs
index ec67fb293..02937f8d8 100644
--- a/src/uppercase/mod.rs
+++ b/src/uppercase/mod.rs
@@ -27,6 +27,12 @@ pub struct Uppercase<'a> {
     iter: Inner<'a>,
 }
 
+impl<'a> Default for Uppercase<'a> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'a> Uppercase<'a> {
     /// Create a new, empty uppercase iterator.
     ///