diff --git a/src/libstd_unicode/char.rs b/src/libstd_unicode/char.rs
index 844ff7a3c1252..5dd9c62775097 100644
--- a/src/libstd_unicode/char.rs
+++ b/src/libstd_unicode/char.rs
@@ -59,7 +59,7 @@ pub use version::UnicodeVersion;
 /// [`to_lowercase`]: ../../std/primitive.char.html#method.to_lowercase
 /// [`char`]: ../../std/primitive.char.html
 #[stable(feature = "rust1", since = "1.0.0")]
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct ToLowercase(CaseMappingIter);
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -81,7 +81,7 @@ impl FusedIterator for ToLowercase {}
 /// [`to_uppercase`]: ../../std/primitive.char.html#method.to_uppercase
 /// [`char`]: ../../std/primitive.char.html
 #[stable(feature = "rust1", since = "1.0.0")]
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct ToUppercase(CaseMappingIter);
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -95,7 +95,7 @@ impl Iterator for ToUppercase {
 #[unstable(feature = "fused", issue = "35602")]
 impl FusedIterator for ToUppercase {}
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 enum CaseMappingIter {
     Three(char, char, char),
     Two(char, char),