diff --git a/HISTORY.txt b/HISTORY.txt
index 1dae3553..6235c00d 100644
--- a/HISTORY.txt
+++ b/HISTORY.txt
@@ -1,3 +1,5 @@
+Unreleased:
+ - Update pexcept to fix shellquote issues in subprocesses.
 8.1.4:
  - Tell users in compatibility mode how to exit the shell.
  - Updated patched pip's vendored pkg-resources.
diff --git a/pipenv/vendor/pexpect/popen_spawn.py b/pipenv/vendor/pexpect/popen_spawn.py
index a795c8a9..0a1b2261 100644
--- a/pipenv/vendor/pexpect/popen_spawn.py
+++ b/pipenv/vendor/pexpect/popen_spawn.py
@@ -15,6 +15,7 @@ except ImportError:
 
 from .spawnbase import SpawnBase, PY3
 from .exceptions import EOF
+from .utils import string_types
 
 class PopenSpawn(SpawnBase):
     if PY3:
@@ -39,10 +40,11 @@ class PopenSpawn(SpawnBase):
             kwargs['startupinfo'] = startupinfo
             kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP
 
-        if not isinstance(cmd, (list, tuple)):
-            cmd = shlex.split(cmd, posix=(os.name == 'posix'))
+        if isinstance(cmd, string_types) and sys.platform != 'win32':
+            cmd = shlex.split(cmd, posix=os.name == 'posix')
 
         self.proc = subprocess.Popen(cmd, **kwargs)
+        self.pid = self.proc.pid
         self.closed = False
         self._buf = self.string_type()
 
diff --git a/pipenv/vendor/pexpect/replwrap.py b/pipenv/vendor/pexpect/replwrap.py
index 118aa9f2..ed0e657d 100644
--- a/pipenv/vendor/pexpect/replwrap.py
+++ b/pipenv/vendor/pexpect/replwrap.py
@@ -114,9 +114,9 @@ def bash(command="bash"):
     # replwrap seeing that as the next prompt, we'll embed the marker characters
     # for invisible characters in the prompt; these show up when inspecting the
     # environment variable, but not when bash displays the prompt.
-    ps1 = PEXPECT_PROMPT[:5] + u'\[\]' + PEXPECT_PROMPT[5:]
-    ps2 = PEXPECT_CONTINUATION_PROMPT[:5] + u'\[\]' + PEXPECT_CONTINUATION_PROMPT[5:]
+    ps1 = PEXPECT_PROMPT[:5] + u'\\[\\]' + PEXPECT_PROMPT[5:]
+    ps2 = PEXPECT_CONTINUATION_PROMPT[:5] + u'\\[\\]' + PEXPECT_CONTINUATION_PROMPT[5:]
     prompt_change = u"PS1='{0}' PS2='{1}' PROMPT_COMMAND=''".format(ps1, ps2)
 
-    return REPLWrapper(child, u'\$', prompt_change,
+    return REPLWrapper(child, u'\\$', prompt_change,
                        extra_init_cmd="export PAGER=cat")
diff --git a/pipenv/vendor/pexpect/utils.py b/pipenv/vendor/pexpect/utils.py
index ae0fe9dc..bafc2805 100644
--- a/pipenv/vendor/pexpect/utils.py
+++ b/pipenv/vendor/pexpect/utils.py
@@ -11,6 +11,11 @@ except NameError:
     # Alias Python2 exception to Python3
     InterruptedError = select.error
 
+if sys.version_info[0] >= 3:
+    string_types = (str,)
+else:
+    string_types = (unicode, str)
+
 
 def is_executable_file(path):
     """Checks that path is an executable regular file, or a symlink towards one.