diff --git a/Project.toml b/Project.toml
index ae8b6c941..557f7bea8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "Mooncake"
 uuid = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 authors = ["Will Tebbutt, Hong Ge, and contributors"]
-version = "0.4.12"
+version = "0.4.13"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
@@ -55,7 +55,7 @@ Graphs = "1"
 JET = "0.9"
 LogDensityProblemsAD = "1"
 LuxLib = "1.2 - 1.3.3"
-MistyClosures = "1"
+MistyClosures = "1.0.3"
 NNlib = "0.9"
 PDMats = "0.11"
 Setfield = "1"
diff --git a/src/interpreter/s2s_reverse_mode_ad.jl b/src/interpreter/s2s_reverse_mode_ad.jl
index aeb5498e7..8c5c30151 100644
--- a/src/interpreter/s2s_reverse_mode_ad.jl
+++ b/src/interpreter/s2s_reverse_mode_ad.jl
@@ -930,14 +930,8 @@ function build_rrule(
             # @show length(stmt(ir.stmts))
             # @show length(stmt(optimised_fwds_ir.stmts))
             # @show length(stmt(optimised_pb_ir.stmts))
-            fwds_oc = MistyClosure(
-                OpaqueClosure(optimised_fwds_ir, shared_data...; do_compile=true),
-                optimised_fwds_ir,
-            )
-            pb_oc = MistyClosure(
-                OpaqueClosure(optimised_pb_ir, shared_data...; do_compile=true),
-                optimised_pb_ir,
-            )
+            fwds_oc = MistyClosure(optimised_fwds_ir, shared_data...; do_compile=true)
+            pb_oc = MistyClosure(optimised_pb_ir, shared_data...; do_compile=true)
 
             # Compute the signature. Needs careful handling with varargs.
             sig = sig_or_mi isa Core.MethodInstance ? sig_or_mi.specTypes : sig_or_mi