diff --git a/mistral/engine/tasks.py b/mistral/engine/tasks.py
index fbeeccb0..d850ce25 100644
--- a/mistral/engine/tasks.py
+++ b/mistral/engine/tasks.py
@@ -14,7 +14,6 @@
 #    limitations under the License.
 
 import abc
-import copy
 import operator
 from oslo_log import log as logging
 from osprofiler import profiler
@@ -241,7 +240,7 @@ class Task(object):
         if not action_name:
             return {}
 
-        env = self.task_ex.in_context.get('__env', {})
+        env = self.wf_ex.context.get('__env', {})
 
         return env.get('__actions', {}).get(action_name, {})
 
@@ -351,12 +350,16 @@ class RegularTask(Task):
         )
 
     def _get_target(self, input_dict):
+        ctx_view = data_flow.ContextView(
+            input_dict,
+            self.ctx,
+            self.wf_ex.context,
+            self.wf_ex.input
+        )
+
         return expr.evaluate_recursively(
             self.task_spec.get_target(),
-            utils.merge_dicts(
-                copy.deepcopy(input_dict),
-                copy.deepcopy(self.ctx)
-            )
+            ctx_view
         )
 
     def _get_action_input(self, ctx=None):
diff --git a/mistral/engine/workflows.py b/mistral/engine/workflows.py
index d2e6ffda..9a53a94e 100644
--- a/mistral/engine/workflows.py
+++ b/mistral/engine/workflows.py
@@ -140,11 +140,6 @@ class Workflow(object):
         # Calculate commands to process next.
         cmds = wf_ctrl.continue_workflow()
 
-        if env:
-            for cmd in cmds:
-                if isinstance(cmd, commands.RunExistingTask):
-                    _update_task_environment(cmd.task_ex, env)
-
         self._continue_workflow(cmds)
 
     def rerun(self, task_ex, reset=True, env=None):
@@ -167,8 +162,6 @@ class Workflow(object):
 
         self.set_state(states.RUNNING, recursive=True)
 
-        _update_task_environment(task_ex, env)
-
         wf_ctrl = wf_base.get_controller(self.wf_ex)
 
         # Calculate commands to process next.
@@ -379,16 +372,6 @@ class Workflow(object):
         )
 
 
-def _update_task_environment(task_ex, env):
-    if env is None:
-        return
-
-    task_ex.in_context['__env'] = utils.merge_dicts(
-        task_ex.in_context['__env'],
-        env
-    )
-
-
 def _get_environment(params):
     env = params.get('env', {})
 
diff --git a/mistral/services/workflows.py b/mistral/services/workflows.py
index 649edc1c..ebfed895 100644
--- a/mistral/services/workflows.py
+++ b/mistral/services/workflows.py
@@ -116,6 +116,7 @@ def update_workflow_execution_env(wf_ex, env):
         )
 
     wf_ex.params['env'] = utils.merge_dicts(wf_ex.params['env'], env)
+
     data_flow.add_environment_to_context(wf_ex)
 
     return wf_ex
diff --git a/mistral/workflow/base.py b/mistral/workflow/base.py
index 3015a7d6..cc7d5dd0 100644
--- a/mistral/workflow/base.py
+++ b/mistral/workflow/base.py
@@ -16,7 +16,6 @@
 #    limitations under the License.
 
 import abc
-import copy
 
 from oslo_log import log as logging
 from osprofiler import profiler
@@ -182,19 +181,7 @@ class WorkflowController(object):
         # to cover 'split' (aka 'merge') use case.
         upstream_task_execs = self._get_upstream_task_executions(task_spec)
 
-        ctx = data_flow.evaluate_upstream_context(upstream_task_execs)
-
-        # TODO(rakhmerov): Seems like we can fully get rid of '__env' in
-        # task context if we are OK to have it only in workflow execution
-        # object (wf_ex.context). Now we can selectively modify env
-        # for some tasks if we resume or re-run a workflow.
-        if self.wf_ex.context:
-            ctx['__env'] = u.merge_dicts(
-                copy.deepcopy(ctx.get('__env', {})),
-                copy.deepcopy(self.wf_ex.context.get('__env', {}))
-            )
-
-        return ctx
+        return data_flow.evaluate_upstream_context(upstream_task_execs)
 
     @abc.abstractmethod
     def _get_upstream_task_executions(self, task_spec):