diff --git a/phf/src/map.rs b/phf/src/map.rs
index 0b5f95a0..fe737aea 100644
--- a/phf/src/map.rs
+++ b/phf/src/map.rs
@@ -39,7 +39,7 @@ pub struct Map<K:'static, V:'static> {
     pub entries: &'static [(K, V)],
 }
 
-impl<K, V> fmt::Show for Map<K, V> where K: fmt::Show, V: fmt::Show {
+impl<K, V> fmt::Debug for Map<K, V> where K: fmt::Debug, V: fmt::Debug {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         try!(write!(fmt, "Map {{"));
         let mut first = true;
diff --git a/phf/src/ordered_map.rs b/phf/src/ordered_map.rs
index 9c042445..9d3d88ff 100644
--- a/phf/src/ordered_map.rs
+++ b/phf/src/ordered_map.rs
@@ -46,7 +46,7 @@ pub struct OrderedMap<K:'static, V:'static> {
     pub entries: &'static [(K, V)],
 }
 
-impl<K, V> fmt::Show for OrderedMap<K, V> where K: fmt::Show, V: fmt::Show {
+impl<K, V> fmt::Debug for OrderedMap<K, V> where K: fmt::Debug, V: fmt::Debug {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         try!(write!(fmt, "OrderedMap {{"));
         let mut first = true;
diff --git a/phf/src/ordered_set.rs b/phf/src/ordered_set.rs
index 05c48a4f..1abc96af 100644
--- a/phf/src/ordered_set.rs
+++ b/phf/src/ordered_set.rs
@@ -37,7 +37,7 @@ pub struct OrderedSet<T:'static> {
     pub map: OrderedMap<T, ()>,
 }
 
-impl<T> fmt::Show for OrderedSet<T> where T: fmt::Show {
+impl<T> fmt::Debug for OrderedSet<T> where T: fmt::Debug {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         try!(write!(fmt, "OrderedSet {{"));
         let mut first = true;
diff --git a/phf/src/set.rs b/phf/src/set.rs
index 46647a5f..ddeb80bf 100644
--- a/phf/src/set.rs
+++ b/phf/src/set.rs
@@ -35,7 +35,7 @@ pub struct Set<T:'static> {
     pub map: Map<T, ()>
 }
 
-impl<T> fmt::Show for Set<T> where T: fmt::Show {
+impl<T> fmt::Debug for Set<T> where T: fmt::Debug {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         try!(write!(fmt, "Set {{"));
         let mut first = true;