diff --git a/sh_expand/bash_expand.py b/sh_expand/bash_expand.py
index b849a95..7fd47af 100644
--- a/sh_expand/bash_expand.py
+++ b/sh_expand/bash_expand.py
@@ -4,7 +4,6 @@
 import sys
 import tempfile
 from collections.abc import Callable
-from contextlib import contextmanager
 from typing import TextIO
 
 import pexpect
@@ -227,14 +226,6 @@ def close(self):
             # TODO: Fails sometimes
             pass
 
-    @contextmanager
-    def subshell(self):
-        try:
-            self.run_command(STR_COMMAND)
-            yield
-        finally:
-            self.run_command("exit")
-
     def expand_word(self, word: str) -> list[str]:
         assert self.is_open
         self.log("To expand with bash:", word)
@@ -335,9 +326,7 @@ def compile_node(ast_object: AstNode, exp_state: BashExpansionState) -> AstNode:
 
 
 def compile_node_pipe(ast_node: PipeNode, exp_state: BashExpansionState):
-    # TODO: Handle shopt -s lastpipe
-    with exp_state.subshell():
-        ast_node.items = [compile_node(item, exp_state) for item in ast_node.items]
+    ast_node.items = [compile_node(item, exp_state) for item in ast_node.items]
     return ast_node
 
 
@@ -355,8 +344,7 @@ def compile_node_command(ast_node: CommandNode, exp_state: BashExpansionState):
 
 
 def compile_node_subshell(ast_node: SubshellNode, exp_state: BashExpansionState):
-    with exp_state.subshell():
-        ast_node.body = compile_node(ast_node.body, exp_state)
+    ast_node.body = compile_node(ast_node.body, exp_state)
     return ast_node
 
 
@@ -391,8 +379,7 @@ def compile_node_redir(ast_node: RedirNode, exp_state: BashExpansionState):
 
 def compile_node_background(ast_node: BackgroundNode, exp_state: BashExpansionState):
     ast_node.redir_list = compile_redirections(ast_node.redir_list, exp_state)
-    with exp_state.subshell():
-        ast_node.node = compile_node(ast_node.node, exp_state)
+    ast_node.node = compile_node(ast_node.node, exp_state)
     return ast_node
 
 
diff --git a/sh_expand/expand.py b/sh_expand/expand.py
index 77c5cf9..30b8188 100644
--- a/sh_expand/expand.py
+++ b/sh_expand/expand.py
@@ -1,5 +1,3 @@
-import copy
-
 from shasta.ast_node import *
 
 from sh_expand.util import log
@@ -442,8 +440,7 @@ def expand_command(command, exp_state: ExpansionState):
 
 def expand_pipe(node, exp_state):
     for i, n in enumerate(node.items):
-        # copy environment to simulate subshell (no outer effect)
-        node.items[i] = expand_command(n, copy.deepcopy(exp_state))
+        node.items[i] = expand_command(n, exp_state)
 
     return node
 
@@ -477,21 +474,16 @@ def expand_and_or_semi(node, exp_state):
     return node
 
 def expand_redir_subshell(node, exp_state):
-    # copy environment to simulate subshell (no outer effect)
-    node.node = expand_command(node.node, copy.deepcopy(exp_state))
-
+    node.node = expand_command(node.node, exp_state)
     return node
 
 def expand_background(node, exp_state):
-    # copy environment to simulate subshell (no outer effect)
-    node.node = expand_command(node.node, copy.deepcopy(exp_state))
-
+    node.node = expand_command(node.node, exp_state)
     return node
 
 def expand_defun(node, exp_state):
     # TODO 2020-11-24 MMG invalidate postional args
-    node.body = expand_command(node.body, copy.deepcopy(exp_state))
-
+    node.body = expand_command(node.body, exp_state)
     return node
 
 def expand_for(node, exp_state):