diff --git a/src/core.rs b/src/core.rs
index 89509de..9bef2ff 100644
--- a/src/core.rs
+++ b/src/core.rs
@@ -86,7 +86,7 @@ pub type ParseResult<'a, Ctx, F> =
 
 /// Trait representing deserialisation rules for [Mentionable]s.
 /// Crucial for [`TypelessMentionable`] and therefore [`Mentionable::points`].
-pub trait Factory<'a, Ctx: 'a + Context>: 'a + Clone {
+pub trait Factory<'a, Ctx: 'a + Context>: 'a + Send + Sync + Clone {
     /// Type of the associated objects.
     type Mtbl: Mentionable<'a, Ctx, Fctr = Self>;
     /// Type of an error that [`Factory::deserialize`] can fail with.
diff --git a/src/core/typeless.rs b/src/core/typeless.rs
index 8367306..6253303 100644
--- a/src/core/typeless.rs
+++ b/src/core/typeless.rs
@@ -12,15 +12,31 @@ pub struct TypelessMentionable<'a, Ctx: 'a + Context> {
 
 type TypelessParsed<'a, Ctx> = Result<TypelessMentionable<'a, Ctx>, Box<dyn 'a + Error>>;
 
-type TypelessDeserialize<'a, Ctx> = dyn 'a
-    + Fn(&mut dyn Deserializer, Rc<dyn Resolver<'a, Ctx>>, &mut Addresses) -> TypelessParsed<'a, Ctx>;
+trait Tde<'a, Ctx: 'a + Context>: 'a + Send + Sync {
+    fn clone_box(&self) -> TdeBox<'a, Ctx>;
 
-type TypelessUnexpectedTail<'a> = dyn 'a + Fn(&[u8]) -> TypelessError<'a>;
+    fn de(
+        &self,
+        deserializer: &mut dyn Deserializer,
+        resolver: Rc<dyn Resolver<'a, Ctx>>,
+        addresses: &mut Addresses,
+    ) -> TypelessParsed<'a, Ctx>;
+}
+
+type TdeBox<'a, Ctx> = Box<dyn Tde<'a, Ctx>>;
+
+trait Tut<'a, Ctx: 'a + Context>: 'a + Send + Sync {
+    fn clone_box(&self) -> TutBox<'a, Ctx>;
+
+    fn ut(&self, tail: &[u8]) -> TypelessError<'a>;
+}
+
+type TutBox<'a, Ctx> = Box<dyn Tut<'a, Ctx>>;
 
 /// See [`Mentionable::points`]/[`TypelessMentionable`].
 pub struct TypelessFactory<'a, Ctx: 'a + Context> {
-    t_deserialize: Rc<TypelessDeserialize<'a, Ctx>>,
-    t_unexpected_tail: Rc<TypelessUnexpectedTail<'a>>,
+    t_deserialize: TdeBox<'a, Ctx>,
+    t_unexpected_tail: TutBox<'a, Ctx>,
 }
 
 impl<'a, Ctx: 'a + Context> Serializable for TypelessMentionable<'a, Ctx> {
@@ -52,8 +68,8 @@ impl<'a, Ctx: 'a + Context> Mentionable<'a, Ctx> for TypelessMentionable<'a, Ctx
 impl<'a, Ctx: 'a + Context> Clone for TypelessFactory<'a, Ctx> {
     fn clone(&self) -> Self {
         Self {
-            t_deserialize: self.t_deserialize.clone(),
-            t_unexpected_tail: self.t_unexpected_tail.clone(),
+            t_deserialize: self.t_deserialize.clone_box(),
+            t_unexpected_tail: self.t_unexpected_tail.clone_box(),
         }
     }
 }
@@ -81,14 +97,14 @@ impl<'a, Ctx: 'a + Context> Factory<'a, Ctx> for TypelessFactory<'a, Ctx> {
         resolver: Rc<dyn Resolver<'a, Ctx>>,
         addresses: &mut Addresses,
     ) -> ParseResult<'a, Ctx, Self> {
-        match (self.t_deserialize)(deserializer, resolver, addresses) {
+        match self.t_deserialize.de(deserializer, resolver, addresses) {
             Ok(mentionable) => Ok(mentionable),
             Err(error) => Err(TypelessError(error)),
         }
     }
 
     fn unexpected_tail(&self, tail: &[u8]) -> Self::ParseError {
-        (self.t_unexpected_tail)(tail)
+        self.t_unexpected_tail.ut(tail)
     }
 }
 
@@ -106,19 +122,42 @@ impl<'a, Ctx: 'a + Context> TypelessMentionable<'a, Ctx> {
     }
 }
 
+impl<'a, Ctx: 'a + Context, F: Factory<'a, Ctx>> Tde<'a, Ctx> for F {
+    fn clone_box(&self) -> TdeBox<'a, Ctx> {
+        Box::new(self.clone())
+    }
+
+    fn de(
+        &self,
+        deserializer: &mut dyn Deserializer,
+        resolver: Rc<dyn Resolver<'a, Ctx>>,
+        addresses: &mut Addresses,
+    ) -> TypelessParsed<'a, Ctx> {
+        match self.deserialize(deserializer, resolver, addresses) {
+            Ok(mentionable) => Ok(TypelessMentionable::from_typed(Rc::new(mentionable))),
+            Err(error) => {
+                let boxed: Box<dyn 'a + Error> = Box::new(error);
+                Err(boxed)
+            }
+        }
+    }
+}
+
+impl<'a, Ctx: 'a + Context, F: Factory<'a, Ctx>> Tut<'a, Ctx> for F {
+    fn clone_box(&self) -> TutBox<'a, Ctx> {
+        Box::new(self.clone())
+    }
+
+    fn ut(&self, tail: &[u8]) -> TypelessError<'a> {
+        TypelessError::from_typed(self.unexpected_tail(tail))
+    }
+}
+
 impl<'a, Ctx: 'a + Context> TypelessFactory<'a, Ctx> {
     pub fn from_typed<F: Factory<'a, Ctx>>(factory: F) -> Self {
-        let tail_factory = factory.clone();
         TypelessFactory {
-            t_deserialize: Rc::new(move |deserializer, resolver, addresses| {
-                match factory.deserialize(deserializer, resolver, addresses) {
-                    Ok(mentionable) => Ok(TypelessMentionable::from_typed(Rc::new(mentionable))),
-                    Err(error) => Err(Box::new(error)),
-                }
-            }),
-            t_unexpected_tail: Rc::new(move |tail| {
-                TypelessError::from_typed(tail_factory.unexpected_tail(tail))
-            }),
+            t_deserialize: Box::new(factory.clone()),
+            t_unexpected_tail: Box::new(factory),
         }
     }
 }
diff --git a/src/std/atomic.rs b/src/std/atomic.rs
index ae792ab..75c2581 100644
--- a/src/std/atomic.rs
+++ b/src/std/atomic.rs
@@ -13,7 +13,7 @@ use super::*;
 
 /// This trait combines functionality of [`Mentionable`] and [`Factory`],
 /// while limiting [`Mentionable::points`] (and corresponding [`Mentionable::topology`]) to an empty sequence.
-pub trait Atomic: 'static + Sized + Clone + Serializable {
+pub trait Atomic: 'static + Send + Sync + Send + Clone + Serializable {
     /// Equivalent of [`Factory::ParseError`].
     type ParseError: Error;
     /// Static equivalent of [`Factory::deserialize`].
diff --git a/src/std/inlining/static_pair.rs b/src/std/inlining/static_pair.rs
index fae1b6c..a7c1255 100644
--- a/src/std/inlining/static_pair.rs
+++ b/src/std/inlining/static_pair.rs
@@ -31,7 +31,7 @@ pub trait StaticPair<'a, Ctx: 'a + Context>:
     'a + StaticPairSerializable<SA = Self::A, SB = Self::B>
 {
     /// [Factory] data. May, depending on the usecase, include factory (factories) on the element(s).
-    type FactoryData: 'a + Clone;
+    type FactoryData: 'a + Send + Sync + Clone;
     /// First element's type. Must equal [`StaticPairSerializable::SA`].
     type A: Mentionable<'a, Ctx, Fctr = Self::FA>;
     /// Second element's type. Must equal [`StaticPairSerializable::SB`].