diff --git a/src/flow/speculative.rs b/src/flow/speculative.rs
index 37e42dc..9dd1586 100644
--- a/src/flow/speculative.rs
+++ b/src/flow/speculative.rs
@@ -1,3 +1,5 @@
+use fail::*;
+
 use crate::func::*;
 
 type Frwa<'a, A, E0, E1, Fallible> =
diff --git a/src/flow/traversible/algorithms/contains.rs b/src/flow/traversible/algorithms/contains.rs
index c5b04c6..ab696c1 100644
--- a/src/flow/traversible/algorithms/contains.rs
+++ b/src/flow/traversible/algorithms/contains.rs
@@ -1,4 +1,4 @@
-use crate::flow::traversible::*;
+use crate::{flow::traversible::*, func::class_prelude::MonadFail};
 
 pub fn n_contains<'a, T: MonadFail<'a, ()>, A: 'a + Clone, D: 'a + PartialEq>(
     comparator: &'a dyn Comparator<A>,
diff --git a/src/flow/traversible/algorithms/subset.rs b/src/flow/traversible/algorithms/subset.rs
index 6d10333..55b6448 100644
--- a/src/flow/traversible/algorithms/subset.rs
+++ b/src/flow/traversible/algorithms/subset.rs
@@ -1,5 +1,6 @@
 use crate::flow::comparator::*;
 use crate::flow::traversible::*;
+use crate::func::class_prelude::MonadFail;
 
 fn and(_l: (), _r: ()) {}
 
diff --git a/src/func.rs b/src/func.rs
index f386cf5..6cccc9a 100644
--- a/src/func.rs
+++ b/src/func.rs
@@ -8,11 +8,12 @@
 //! * <https://hackage.haskell.org/package/base-4.18.0.0/docs/Control-Monad.html>
 
 mod applicative_select;
+pub mod class_prelude;
 pub mod context;
 mod controlflow;
 pub mod derivations;
 mod extensions;
-mod fail;
+pub mod fail;
 pub mod instances;
 pub mod shared;
 #[cfg(test)]
@@ -27,8 +28,7 @@ pub use self::applicative_select::{
 };
 use self::controlflow::{BindableMut, ControlFlowInstance};
 pub use self::controlflow::{Iterative, IterativeWrapped};
-pub use self::extensions::{MonadExt, MonadFailAnyExt};
-pub use self::fail::{Fail, MonadFail, MonadFailAny, WrapE};
+pub use self::extensions::MonadExt;
 #[cfg(doc)]
 use self::instances::stackless::StacklessInstance;
 
diff --git a/src/func/class_prelude.rs b/src/func/class_prelude.rs
new file mode 100644
index 0000000..24edd46
--- /dev/null
+++ b/src/func/class_prelude.rs
@@ -0,0 +1,11 @@
+pub use super::{
+    extensions::MonadExt,
+    fail::{Fail, MonadFail, MonadFailAny, MonadFailAnyExt, WrapE},
+    instances,
+    shared::{SharedFunctor, SharedFunctorAny},
+    Applicative, ApplicativeLA2, ApplicativeSelect, ApplicativeSelectExt, ApplicativeSeq,
+    ApplicativeTuple, ControlFlow, Functor, Iterative, IterativeWrapped, LocalFunctor, Monad, Pure,
+    Selected, SelectedWrapped, WeakFunctor, WeakFunctorAny, Wrap,
+};
+#[cfg(test)]
+pub use super::{test_suite, tests};
diff --git a/src/func/context.rs b/src/func/context.rs
index f3f58f0..ef74a95 100644
--- a/src/func/context.rs
+++ b/src/func/context.rs
@@ -1,4 +1,4 @@
-use super::*;
+use super::{fail::*, *};
 
 pub type WrapC<'a, A, Ctx> = Wrap<'a, A, <Ctx as FunctorContext<'a>>::T>;
 
diff --git a/src/func/extensions.rs b/src/func/extensions.rs
index 0e2e7e8..e7f18cb 100644
--- a/src/func/extensions.rs
+++ b/src/func/extensions.rs
@@ -20,15 +20,3 @@ pub trait MonadExt<'a>: Monad<'a> {
         Self::join(Self::la2(fa, fb, f))
     }
 }
-
-pub trait MonadFailAnyExt<'a>: MonadFailAny<'a> {
-    fn pure<E: 'a, A: 'a>(a: A) -> WrapE<'a, A, E, Self> {
-        <Self::W<E> as Pure>::pure(a)
-    }
-
-    fn fail<E: 'a, A: 'a>(e: E) -> WrapE<'a, A, E, Self> {
-        <Self::W<E> as Fail<E>>::fail(e)
-    }
-}
-
-impl<'a, Fallible: ?Sized + MonadFailAny<'a>> MonadFailAnyExt<'a> for Fallible {}
diff --git a/src/func/fail.rs b/src/func/fail.rs
index fd75f4c..8280cfe 100644
--- a/src/func/fail.rs
+++ b/src/func/fail.rs
@@ -84,3 +84,15 @@ pub trait MonadFailAny<'a>: 'a {
 }
 
 pub type WrapE<'a, A, E, Fallible> = Wrap<'a, A, <Fallible as MonadFailAny<'a>>::W<E>>;
+
+pub trait MonadFailAnyExt<'a>: MonadFailAny<'a> {
+    fn pure<E: 'a, A: 'a>(a: A) -> WrapE<'a, A, E, Self> {
+        <Self::W<E> as Pure>::pure(a)
+    }
+
+    fn fail<E: 'a, A: 'a>(e: E) -> WrapE<'a, A, E, Self> {
+        <Self::W<E> as Fail<E>>::fail(e)
+    }
+}
+
+impl<'a, Fallible: ?Sized + MonadFailAny<'a>> MonadFailAnyExt<'a> for Fallible {}
diff --git a/src/func/instances.rs b/src/func/instances.rs
index 6169f7c..8240891 100644
--- a/src/func/instances.rs
+++ b/src/func/instances.rs
@@ -21,7 +21,7 @@
 //! [^research]: instances used for research purposes to enhance the abstract interfaces.
 
 #[cfg(doc)]
-use crate::func::*;
+use crate::func::{fail::*, *};
 
 pub mod composition;
 pub mod effect;
diff --git a/src/func/instances/composition.rs b/src/func/instances/composition.rs
index fd52493..25a9666 100644
--- a/src/func/instances/composition.rs
+++ b/src/func/instances/composition.rs
@@ -4,9 +4,9 @@
 //!
 //! For [`future`]-[`result`] composition, see [`tryfuture`].
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 pub struct CompositionInstance<U, V>(U, V);
 
diff --git a/src/func/instances/effect.rs b/src/func/instances/effect.rs
index 7524627..97ab7a0 100644
--- a/src/func/instances/effect.rs
+++ b/src/func/instances/effect.rs
@@ -4,9 +4,9 @@
 //!
 //! For no extra data, see [`solo`].
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 /// Metadata type.
 pub trait Effect {
diff --git a/src/func/instances/future.rs b/src/func/instances/future.rs
index 70be8bb..2440cd5 100644
--- a/src/func/instances/future.rs
+++ b/src/func/instances/future.rs
@@ -12,9 +12,9 @@ use futures::{
     join, FutureExt,
 };
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 pub struct FutureInstance;
 
diff --git a/src/func/instances/lazy.rs b/src/func/instances/lazy.rs
index 97ad3cc..2a5b620 100644
--- a/src/func/instances/lazy.rs
+++ b/src/func/instances/lazy.rs
@@ -9,9 +9,9 @@
 
 use std::{cell::RefCell, rc::Rc};
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 pub struct LazyInstance;
 
diff --git a/src/func/instances/option.rs b/src/func/instances/option.rs
index 297d1e5..da3604b 100644
--- a/src/func/instances/option.rs
+++ b/src/func/instances/option.rs
@@ -9,9 +9,9 @@
 //!
 //! For values that are never [`None`], see [`solo`].
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 #[derive(SharedFunctorAny)]
 pub struct OptionInstance;
diff --git a/src/func/instances/overload.rs b/src/func/instances/overload.rs
index 5813d8f..9ee1517 100644
--- a/src/func/instances/overload.rs
+++ b/src/func/instances/overload.rs
@@ -6,9 +6,9 @@
 
 use std::marker::PhantomData;
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 pub struct OverloadInstance<T, O>(T, O);
 
diff --git a/src/func/instances/result.rs b/src/func/instances/result.rs
index d891743..d48a6e8 100644
--- a/src/func/instances/result.rs
+++ b/src/func/instances/result.rs
@@ -9,9 +9,9 @@
 //!
 //! For values that are never [`Err`], see [`solo`].
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 #[derive(SharedFunctorAny)]
 pub struct ResultInstance<E>(E);
diff --git a/src/func/instances/solo.rs b/src/func/instances/solo.rs
index b278c0b..555ce76 100644
--- a/src/func/instances/solo.rs
+++ b/src/func/instances/solo.rs
@@ -4,9 +4,9 @@
 //!
 //! For abstracting away dealing with fallible data, see [`option`]/[`result`].
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 #[derive(SharedFunctorAny)]
 pub struct SoloInstance;
diff --git a/src/func/instances/stackless.rs b/src/func/instances/stackless.rs
index ef50c50..5712a01 100644
--- a/src/func/instances/stackless.rs
+++ b/src/func/instances/stackless.rs
@@ -5,10 +5,10 @@
 
 use std::{cell::Cell, rc::Rc};
 
-use crate::func::derivations::*;
+use crate::func::class_prelude::*;
+use crate::func::derivations::{ApplicativeLA2ViaSeq, ApplicativeTupleViaLA2};
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::*;
 
 enum EvalTree<'a> {
     Atom(Box<dyn 'a + FnOnce() -> Oet<'a>>),
diff --git a/src/func/instances/tryfuture.rs b/src/func/instances/tryfuture.rs
index 4907da6..4d2f01e 100644
--- a/src/func/instances/tryfuture.rs
+++ b/src/func/instances/tryfuture.rs
@@ -11,9 +11,9 @@ use futures::{
     try_join, FutureExt,
 };
 
+use crate::func::class_prelude::*;
 #[cfg(doc)]
 use crate::func::instances::*;
-use crate::func::{shared::*, *};
 
 pub struct TryFutureInstance<E>(E);
 
diff --git a/src/rcore/context.rs b/src/rcore/context.rs
index 030dd5a..fbe8685 100644
--- a/src/rcore/context.rs
+++ b/src/rcore/context.rs
@@ -1,3 +1,5 @@
+use fail::*;
+
 use super::*;
 
 /// Execution context.
diff --git a/src/rstd/fallible.rs b/src/rstd/fallible.rs
index 7a0868b..91ab300 100644
--- a/src/rstd/fallible.rs
+++ b/src/rstd/fallible.rs
@@ -1,5 +1,7 @@
 //! Shorthands for using [`Context::Fallible`].
 
+use fail::*;
+
 use crate::func::context::*;
 
 use super::*;