diff --git a/src/stream/stream/flatten.rs b/src/stream/stream/flatten.rs
index d44fab0..bc1bee3 100644
--- a/src/stream/stream/flatten.rs
+++ b/src/stream/stream/flatten.rs
@@ -13,27 +13,27 @@ pin_project! {
     /// [`flat_map`]: trait.Stream.html#method.flat_map
     /// [`Stream`]: trait.Stream.html
     #[allow(missing_debug_implementations)]
-    pub struct FlatMap<S: Stream, U: IntoStream, F> {
+    pub struct FlatMap<S, U, T, F> {
         #[pin]
-        inner: FlattenCompat<Map<S, F, S::Item, U>, U>,
+        inner: FlattenCompat<Map<S, F, T, U>, U>,
     }
 }
 
-impl<S, U, F> FlatMap<S, U, F>
+impl<S, U, F> FlatMap<S, U, S::Item, F>
 where
     S: Stream,
     U: IntoStream,
     F: FnMut(S::Item) -> U,
 {
 
-    pub fn new(stream: S, f: F) -> FlatMap<S, U, F> {
+    pub fn new(stream: S, f: F) -> FlatMap<S, U, S::Item, F> {
         FlatMap {
             inner: FlattenCompat::new(stream.map(f)),
         }
     }
 }
 
-impl<S, U, F> Stream for FlatMap<S, U, F>
+impl<S, U, F> Stream for FlatMap<S, U, S::Item, F>
 where
     S: Stream<Item: IntoStream<IntoStream = U, Item = U::Item>> + std::marker::Unpin,
     U: Stream + std::marker::Unpin,
@@ -53,22 +53,19 @@ pin_project!{
     /// [`flatten`]: trait.Stream.html#method.flatten
     /// [`Stream`]: trait.Stream.html
     #[allow(missing_debug_implementations)]
-    pub struct Flatten<S: Stream>
-    where
-        S::Item: IntoStream,
-    {
+    pub struct Flatten<S, U> {
         #[pin]
-        inner: FlattenCompat<S, <S::Item as IntoStream>::IntoStream>,
+        inner: FlattenCompat<S, U>
     }
 }
 
-impl<S: Stream<Item: IntoStream>> Flatten<S> {
-    pub fn new(stream: S) -> Flatten<S> {
+impl<S: Stream<Item: IntoStream>> Flatten<S, S::Item> {
+    pub fn new(stream: S) -> Flatten<S, S::Item> {
         Flatten { inner: FlattenCompat::new(stream) }
     }
 }
 
-impl<S, U> Stream for Flatten<S>
+impl<S, U> Stream for Flatten<S, <S::Item as IntoStream>::IntoStream>
 where
     S: Stream<Item: IntoStream<IntoStream = U, Item = U::Item>> + std::marker::Unpin,
     U: Stream + std::marker::Unpin,
diff --git a/src/stream/stream/mod.rs b/src/stream/stream/mod.rs
index 8ad8cdc..c994a8f 100644
--- a/src/stream/stream/mod.rs
+++ b/src/stream/stream/mod.rs
@@ -30,6 +30,7 @@ mod filter;
 mod filter_map;
 mod find;
 mod find_map;
+mod flatten;
 mod fold;
 mod for_each;
 mod fuse;
@@ -77,6 +78,7 @@ use try_for_each::TryForEeachFuture;
 
 pub use chain::Chain;
 pub use filter::Filter;
+pub use flatten::{FlatMap, Flatten};
 pub use fuse::Fuse;
 pub use inspect::Inspect;
 pub use map::Map;
@@ -99,10 +101,8 @@ cfg_unstable! {
     use crate::stream::into_stream::IntoStream;
 
     pub use merge::Merge;
-    pub use flatten::{FlatMap, Flatten};
 
     mod merge;
-    mod flatten;
 }
 
 extension_trait! {
@@ -588,9 +588,7 @@ extension_trait! {
             # });
             ```
         "#]
-        #[cfg(feature = "unstable")]
-        #[cfg_attr(feature = "docs", doc(cfg(unstable)))]
-        fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
+        fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, Self::Item, F>
             where
                 Self: Sized,
                 U: IntoStream,
@@ -622,9 +620,7 @@ extension_trait! {
 
             # });
         "#]
-        #[cfg(feature = "unstable")]
-        #[cfg_attr(feature = "docs", doc(cfg(unstable)))]
-        fn flatten(self) -> Flatten<Self>
+        fn flatten(self) -> Flatten<Self, Self::Item>
         where
             Self: Sized,
             Self::Item: IntoStream,