diff --git a/autoload/ale/python.vim b/autoload/ale/python.vim
index 0766551d..615986f9 100644
--- a/autoload/ale/python.vim
+++ b/autoload/ale/python.vim
@@ -100,15 +100,18 @@ endfunction
 " a string of them to prefix linter commands with.
 function! ale#python#AutoVirtualenvEnvString(buffer) abort
     let l:venv_dir = ale#python#FindVirtualenv(a:buffer)
-    let l:pathsep = has('win32') ? ';' : ':'
 
     if !empty(l:venv_dir)
-        let l:vars = [
-        \   ['PATH', l:venv_dir . s:sep . s:bin_dir . l:pathsep . $PATH],
-        \]
+        let l:strs = [ ]
 
-        " We don't need a space between var as ale#Env adds one.
-        return join(map(l:vars, 'ale#Env(v:val[0], v:val[1])'), '')
+        " expand PATH correctly inside of the appropriate shell.
+        if has('win32')
+            call add(l:strs, 'set PATH=' . ale#Escape(l:venv_dir) . ';%PATH% && ')
+        else
+            call add(l:strs, 'PATH=' . ale#Escape(l:venv_dir) . '":$PATH" ')
+        endif
+
+        return join(l:strs, '')
     endif
 
     return ''
diff --git a/test/linter/test_jedils.vader b/test/linter/test_jedils.vader
index 3d52b1b5..5ffd22d8 100644
--- a/test/linter/test_jedils.vader
+++ b/test/linter/test_jedils.vader
@@ -31,8 +31,9 @@ Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
   let b:sep = has('win32') ? ';' : ':'
   let b:executable = ale#path#Simplify(b:venv_bin . '/jedi-language-server')
 
-  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  AssertLinter b:executable, ale#python#AutoVirtualenvEnvString(bufnr(''))
   \   . ale#Escape(b:executable)
+  Assert !empty(ale#python#AutoVirtualenvEnvString(bufnr('')))
 
 Execute(You should be able to override the jedi-language-server virtualenv lookup):
   call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
diff --git a/test/linter/test_pylsp.vader b/test/linter/test_pylsp.vader
index 1bc56c73..580cec17 100644
--- a/test/linter/test_pylsp.vader
+++ b/test/linter/test_pylsp.vader
@@ -52,8 +52,9 @@ Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
   let b:sep = has('win32') ? ';' : ':'
   let b:executable = ale#path#Simplify(b:venv_bin . '/pylsp')
 
-  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  AssertLinter b:executable, ale#python#AutoVirtualenvEnvString(bufnr(''))
   \   . ale#Escape(b:executable)
+  Assert !empty(ale#python#AutoVirtualenvEnvString(bufnr('')))
 
 Execute(You should be able to override the pylsp virtualenv lookup):
   call ale#test#SetFilename('../test-files/python/with_virtualenv/subdir/foo/bar.py')
diff --git a/test/linter/test_pyright.vader b/test/linter/test_pyright.vader
index c99877ab..6730d135 100644
--- a/test/linter/test_pyright.vader
+++ b/test/linter/test_pyright.vader
@@ -144,8 +144,9 @@ Execute(virtualenv vars should be used when ale_python_auto_virtualenv = 1):
   let b:sep = has('win32') ? ';' : ':'
   let b:executable = ale#path#Simplify(b:venv_bin . '/pyright-langserver')
 
-  AssertLinter b:executable, ale#Env('PATH', b:venv_bin . b:sep . $PATH)
+  AssertLinter b:executable, ale#python#AutoVirtualenvEnvString(bufnr(''))
   \   . ale#Escape(b:executable) . ' --stdio'
+  Assert !empty(ale#python#AutoVirtualenvEnvString(bufnr('')))
 
 Execute(Setting executable to 'pipenv' should append 'run pyright'):
   call ale#test#SetFilename('../test-files')
diff --git a/test/test_python_virtualenv.vader b/test/test_python_virtualenv.vader
index b44c5fa2..cb49d315 100644
--- a/test/test_python_virtualenv.vader
+++ b/test/test_python_virtualenv.vader
@@ -10,3 +10,14 @@ Execute(ale#python#FindVirtualenv falls back to $VIRTUAL_ENV when no directories
   \  ale#python#FindVirtualenv(bufnr('%')),
   \  '/opt/example/',
   \  'Expected VIRTUAL_ENV environment variable to be used, but it was not'
+
+Execute(ale#python#AutoVirtualenvEnvString should return the correct values):
+  if has('win32')
+    AssertEqual
+    \ 'set PATH=/opt/example/;%PATH% && ',
+    \ ale#python#AutoVirtualenvEnvString(bufnr(''))
+  else
+    AssertEqual
+    \ 'PATH=''/opt/example/''":$PATH" ',
+    \ ale#python#AutoVirtualenvEnvString(bufnr(''))
+  endif