diff --git a/Project.toml b/Project.toml
index b415ac69..7d871e50 100644
--- a/Project.toml
+++ b/Project.toml
@@ -3,7 +3,7 @@ uuid = "6f1fad26-d15e-5dc8-ae53-837a1d7b8c9f"
 license = "MIT"
 desc = "Tape based task copying in Turing"
 repo = "https://github.com/TuringLang/Libtask.jl.git"
-version = "0.8.3"
+version = "0.8.4"
 
 [deps]
 FunctionWrappers = "069b7b12-0de2-55c6-9aab-29f3d0a68a2e"
diff --git a/src/tapedfunction.jl b/src/tapedfunction.jl
index 8f2e27b2..963fea47 100644
--- a/src/tapedfunction.jl
+++ b/src/tapedfunction.jl
@@ -62,7 +62,7 @@ mutable struct TapedFunction{F, TapeType}
 
     function TapedFunction{F, T}(f::F, args...; cache=false, deepcopy_types=Union{}) where {F, T}
         args_type = _accurate_typeof.(args)
-        cache_key = (f, args_type...)
+        cache_key = (f, deepcopy_types, args_type...)
 
         if cache && haskey(TRCache, cache_key) # use cache
             cached_tf = TRCache[cache_key]::TapedFunction{F, T}