diff --git a/prusti-encoder/src/encoders/type/lifted/cast.rs b/prusti-encoder/src/encoders/type/lifted/cast.rs
index 81d5e0943a0..f9c5a5c87bc 100644
--- a/prusti-encoder/src/encoders/type/lifted/cast.rs
+++ b/prusti-encoder/src/encoders/type/lifted/cast.rs
@@ -192,7 +192,7 @@ where
                 .require_local::<RustTyCastersEnc<T>>(task_key.actual)
                 .unwrap();
             if let CastersEncOutputRef::Casters { make_generic, .. } = generic_cast.cast {
-                GenericCastOutputRef::Cast(Cast::new(T::to_generic_applicator(make_generic), &[]))
+                GenericCastOutputRef::Cast(Cast::new(T::to_generic_applicator(make_generic), generic_cast.ty_args))
             } else {
                 unreachable!()
             }
diff --git a/prusti-encoder/src/encoders/type/lifted/casters.rs b/prusti-encoder/src/encoders/type/lifted/casters.rs
index a57b36e36ba..fceee121ee9 100644
--- a/prusti-encoder/src/encoders/type/lifted/casters.rs
+++ b/prusti-encoder/src/encoders/type/lifted/casters.rs
@@ -20,10 +20,16 @@ impl CastTypePure {
         casters: &Casters<'vir, Self>,
         vcx: &'vir vir::VirCtxt<'_>,
         snap: vir::ExprGen<'vir, Curr, Next>,
+        ty_args: &'vir [LiftedTy<'vir, LiftedGeneric<'vir>>],
     ) -> vir::ExprGen<'vir, Curr, Next> {
         match casters {
             CastFunctionsOutputRef::AlreadyGeneric => snap,
-            CastFunctionsOutputRef::Casters { make_generic, .. } => make_generic.apply(vcx, [snap]),
+            CastFunctionsOutputRef::Casters { make_generic, .. } => make_generic.apply(
+                vcx,
+                &std::iter::once(snap)
+                    .chain(ty_args.iter().map(|t| t.expr(vcx)))
+                    .collect::<Vec<_>>(),
+            ),
         }
     }
 }
@@ -194,7 +200,7 @@ impl<G: Copy, C> CastersEncOutputRef<G, C> {
     }
 }
 
-pub type MakeGenericCastFunction<'vir> = FunctionIdent<'vir, UnaryArity<'vir>>;
+pub type MakeGenericCastFunction<'vir> = FunctionIdent<'vir, UnknownArity<'vir>>;
 pub type MakeConcreteCastFunction<'vir> = FunctionIdent<'vir, UnknownArity<'vir>>;
 
 /// Takes as input the most generic version (c.f. [`MostGenericTy`]) of a Rust
@@ -239,21 +245,23 @@ impl TaskEncoder for CastersEnc<CastTypePure> {
                 .unwrap()
                 .ty_constructor;
 
-            let make_generic_arg_tys = [self_ty];
-            let make_generic_ident = FunctionIdent::new(
-                vir::vir_format_identifier!(vcx, "make_generic_s_{base_name}"),
-                UnaryArity::new(vcx.alloc(make_generic_arg_tys)),
-                generic_ref.param_snapshot,
-            );
-
-            let make_concrete_ty_params = ty
+            let ty_params = ty
                 .generics()
                 .into_iter()
                 .map(|g| deps.require_ref::<LiftedGenericEnc>(*g).unwrap())
                 .collect::<Vec<_>>();
 
+            let make_generic_arg_tys = std::iter::once(self_ty)
+                .chain(ty_params.iter().map(|t| t.ty()))
+                .collect::<Vec<_>>();
+            let make_generic_ident = FunctionIdent::new(
+                vir::vir_format_identifier!(vcx, "make_generic_s_{base_name}"),
+                UnknownArity::new(vcx.alloc(make_generic_arg_tys)),
+                generic_ref.param_snapshot,
+            );
+
             let make_concrete_arg_tys = std::iter::once(generic_ref.param_snapshot)
-                .chain(make_concrete_ty_params.iter().map(|t| t.ty()))
+                .chain(ty_params.iter().map(|t| t.ty()))
                 .collect::<Vec<_>>();
 
             let make_concrete_ident = FunctionIdent::new(
@@ -272,9 +280,12 @@ impl TaskEncoder for CastersEnc<CastTypePure> {
             let make_generic_arg = vcx.mk_local_decl("self", self_ty);
             let make_generic_expr = vcx.mk_local_ex(make_generic_arg.name, make_generic_arg.ty);
 
-            let make_generic_arg_decls = vcx.alloc_slice(&[make_generic_arg]);
+            let make_generic_arg_decls = vcx.alloc_slice(&std::iter::once(make_generic_arg)
+                .chain(ty_params.iter().map(|t| t.decl()))
+                .collect::<Vec<_>>()
+            );
 
-            let make_concrete_ty_param_exprs = make_concrete_ty_params
+            let make_concrete_ty_param_exprs = ty_params
                 .iter()
                 .map(|t| t.expr(vcx))
                 .collect::<Vec<_>>();
@@ -319,7 +330,7 @@ impl TaskEncoder for CastersEnc<CastTypePure> {
             let make_concrete_snap_arg_decl = vcx.mk_local_decl("snap", generic_ref.param_snapshot);
             let make_concrete_arg_decls = vcx.alloc_slice(
                 &std::iter::once(make_concrete_snap_arg_decl)
-                    .chain(make_concrete_ty_params.iter().map(|t| t.decl()))
+                    .chain(ty_params.iter().map(|t| t.decl()))
                     .collect::<Vec<_>>(),
             );
 
@@ -331,8 +342,15 @@ impl TaskEncoder for CastersEnc<CastTypePure> {
                 &make_concrete_ty_param_exprs,
             );
 
+            let arg_ty_exprs = ty_params
+                .iter()
+                .map(|t| vcx.mk_local_ex(t.decl().name, t.decl().ty))
+                .collect::<Vec<_>>();
+            let make_generic_args = std::iter::once(vcx.mk_result(self_ty))
+                .chain(arg_ty_exprs)
+                .collect::<Vec<_>>();
             let make_concrete_post = vcx.mk_eq_expr(
-                make_generic_ident.apply(vcx, [vcx.mk_result(self_ty)]),
+                make_generic_ident.apply(vcx, &make_generic_args),
                 vcx.mk_local_ex(
                     make_concrete_snap_arg_decl.name,
                     make_concrete_snap_arg_decl.ty,
@@ -454,14 +472,18 @@ impl TaskEncoder for CastersEnc<CastTypeImpure> {
 
             let generic_predicate = vcx.mk_predicate_app_expr(generic_predicate);
 
+            let make_generic_pure_arg_exprs = std::iter::once(concrete_snap)
+                .chain(arg_ty_exprs.into_iter())
+                .collect::<Vec<_>>();
+
             let make_generic_same_snap = vcx.mk_eq_expr(
-                vcx.mk_old_expr(make_generic_pure.apply(vcx, [concrete_snap])),
+                vcx.mk_old_expr(make_generic_pure.apply(vcx, &make_generic_pure_arg_exprs)),
                 generic_snap,
             );
 
             let make_concrete_same_snap = vcx.mk_eq_expr(
                 vcx.mk_old_expr(generic_snap),
-                make_generic_pure.apply(vcx, [concrete_snap]),
+                make_generic_pure.apply(vcx, &make_generic_pure_arg_exprs),
             );
 
             let make_generic = vcx.mk_method(
diff --git a/prusti-encoder/src/encoders/type/lifted/rust_ty_cast.rs b/prusti-encoder/src/encoders/type/lifted/rust_ty_cast.rs
index 7164279ba67..3a14cfcd40f 100644
--- a/prusti-encoder/src/encoders/type/lifted/rust_ty_cast.rs
+++ b/prusti-encoder/src/encoders/type/lifted/rust_ty_cast.rs
@@ -61,7 +61,7 @@ impl<'vir> RustTyGenericCastEncOutput<'vir, CastFunctionsOutputRef<'vir>> {
         vcx: &'vir vir::VirCtxt<'tcx>,
         snap: vir::ExprGen<'vir, Curr, Next>,
     ) -> vir::ExprGen<'vir, Curr, Next> {
-        CastTypePure::cast_to_generic_if_necessary(&self.cast, vcx, snap)
+        CastTypePure::cast_to_generic_if_necessary(&self.cast, vcx, snap, self.ty_args)
     }
 }