diff --git a/parsl/executors/execute_task.py b/parsl/executors/execute_task.py
index 5bcd79dda6..41c2f3cc9b 100644
--- a/parsl/executors/execute_task.py
+++ b/parsl/executors/execute_task.py
@@ -7,7 +7,7 @@ def execute_task(bufs: bytes):
     """Deserialize the buffer and execute the task.
     Returns the result or throws exception.
     """
-    f, args, kwargs, resource_spec = unpack_res_spec_apply_message(bufs, copy=False)
+    f, args, kwargs, resource_spec = unpack_res_spec_apply_message(bufs)
 
     for varname in resource_spec:
         envname = "PARSL_" + str(varname).upper()
diff --git a/parsl/executors/high_throughput/mpi_resource_management.py b/parsl/executors/high_throughput/mpi_resource_management.py
index 09745421d1..ac02e0c419 100644
--- a/parsl/executors/high_throughput/mpi_resource_management.py
+++ b/parsl/executors/high_throughput/mpi_resource_management.py
@@ -160,9 +160,7 @@ def put_task(self, task_package: dict):
         """Schedule task if resources are available otherwise backlog the task"""
         user_ns = locals()
         user_ns.update({"__builtins__": __builtins__})
-        _f, _args, _kwargs, resource_spec = unpack_res_spec_apply_message(
-            task_package["buffer"], user_ns, copy=False
-        )
+        _f, _args, _kwargs, resource_spec = unpack_res_spec_apply_message(task_package["buffer"])
 
         nodes_needed = resource_spec.get("num_nodes")
         if nodes_needed:
diff --git a/parsl/executors/radical/rpex_worker.py b/parsl/executors/radical/rpex_worker.py
index 09482d8d01..90243b558a 100644
--- a/parsl/executors/radical/rpex_worker.py
+++ b/parsl/executors/radical/rpex_worker.py
@@ -33,7 +33,7 @@ def _dispatch_proc(self, task):
 
         try:
             buffer = rp.utils.deserialize_bson(task['description']['executable'])
-            func, args, kwargs, _resource_spec = unpack_res_spec_apply_message(buffer, {}, copy=False)
+            func, args, kwargs, _resource_spec = unpack_res_spec_apply_message(buffer)
             ret = remote_side_bash_executor(func, *args, **kwargs)
             exc = (None, None)
             val = None
diff --git a/parsl/executors/workqueue/exec_parsl_function.py b/parsl/executors/workqueue/exec_parsl_function.py
index 06a86a5c8d..d19d92efe6 100644
--- a/parsl/executors/workqueue/exec_parsl_function.py
+++ b/parsl/executors/workqueue/exec_parsl_function.py
@@ -94,7 +94,7 @@ def unpack_source_code_function(function_info, user_namespace):
 
 def unpack_byte_code_function(function_info, user_namespace):
     from parsl.serialize import unpack_apply_message
-    func, args, kwargs = unpack_apply_message(function_info["byte code"], user_namespace, copy=False)
+    func, args, kwargs = unpack_apply_message(function_info["byte code"])
     return (func, 'parsl_function_name', args, kwargs)
 
 
diff --git a/parsl/serialize/facade.py b/parsl/serialize/facade.py
index f8e76f174b..2e02e2b983 100644
--- a/parsl/serialize/facade.py
+++ b/parsl/serialize/facade.py
@@ -87,16 +87,16 @@ def pack_res_spec_apply_message(func: Any, args: Any, kwargs: Any, resource_spec
     return pack_apply_message(func, args, (kwargs, resource_specification), buffer_threshold=buffer_threshold)
 
 
-def unpack_apply_message(packed_buffer: bytes, user_ns: Any = None, copy: Any = False) -> List[Any]:
+def unpack_apply_message(packed_buffer: bytes) -> List[Any]:
     """ Unpack and deserialize function and parameters
     """
     return [deserialize(buf) for buf in unpack_buffers(packed_buffer)]
 
 
-def unpack_res_spec_apply_message(packed_buffer: bytes, user_ns: Any = None, copy: Any = False) -> List[Any]:
+def unpack_res_spec_apply_message(packed_buffer: bytes) -> List[Any]:
     """ Unpack and deserialize function, parameters, and resource_specification
     """
-    func, args, (kwargs, resource_spec) = unpack_apply_message(packed_buffer, user_ns=user_ns, copy=copy)
+    func, args, (kwargs, resource_spec) = unpack_apply_message(packed_buffer)
     return [func, args, kwargs, resource_spec]