diff --git a/cibuildwheel/linux.py b/cibuildwheel/linux.py
index cd7a7136..9b6ab4d1 100644
--- a/cibuildwheel/linux.py
+++ b/cibuildwheel/linux.py
@@ -1,7 +1,6 @@
 from __future__ import print_function
 import os, subprocess, sys
 from collections import namedtuple
-from .util import prepare_command
 
 try:
     from shlex import quote as shlex_quote
@@ -105,9 +104,7 @@ def build(project_dir, package_name, output_dir, test_command, test_requires, be
             test_command=shlex_quote(
                 test_command.format(project='/project') if test_command else ''
             ),
-            before_build=shlex_quote(
-                prepare_command(before_build, python='python', pip='pip') if before_build else ''
-            ),
+            before_build=shlex_quote(before_build or ''),
             environment_exports='\n'.join(environment.as_shell_commands()),
         )
 
diff --git a/cibuildwheel/macos.py b/cibuildwheel/macos.py
index 836a7189..71a5716d 100644
--- a/cibuildwheel/macos.py
+++ b/cibuildwheel/macos.py
@@ -7,8 +7,6 @@ try:
 except ImportError:
     from pipes import quote as shlex_quote
 
-from .util import prepare_command
-
 
 def build(project_dir, package_name, output_dir, test_command, test_requires, before_build, skip, environment):
     PythonConfiguration = namedtuple('PythonConfiguration', ['version', 'identifier', 'url'])
@@ -60,18 +58,15 @@ def build(project_dir, package_name, output_dir, test_command, test_requires, be
         ])
         env = environment.as_dictionary(prev_environment=env)
 
-        python = 'python3' if config.version[0] == '3' else 'python2'
-        pip = 'pip3' if config.version[0] == '3' else 'pip2'
-
         # check what version we're on
-        call(['which', python], env=env)
-        call([python, '--version'], env=env)
+        call(['which', 'python'], env=env)
+        call(['python', '--version'], env=env)
 
         # install pip & wheel
-        call([python, get_pip_script, '--no-setuptools', '--no-wheel'], env=env)
-        call([pip, '--version'], env=env)
-        call([pip, 'install', 'wheel'], env=env)
-        call([pip, 'install', 'delocate'], env=env)
+        call(['python', get_pip_script, '--no-setuptools', '--no-wheel'], env=env)
+        call(['pip', '--version'], env=env)
+        call(['pip', 'install', 'wheel'], env=env)
+        call(['pip', 'install', 'delocate'], env=env)
 
         # setup dirs
         if os.path.exists('/tmp/built_wheel'):
@@ -83,11 +78,10 @@ def build(project_dir, package_name, output_dir, test_command, test_requires, be
 
         # run the before_build command
         if before_build:
-            before_build_prepared = prepare_command(before_build, python=python, pip=pip)
-            call(before_build_prepared, env=env, shell=True)
+            call(before_build, env=env, shell=True)
 
         # build the wheel
-        call([pip, 'wheel', abs_project_dir, '-w', '/tmp/built_wheel', '--no-deps'], env=env)
+        call(['pip', 'wheel', abs_project_dir, '-w', '/tmp/built_wheel', '--no-deps'], env=env)
         built_wheel = glob('/tmp/built_wheel/*.whl')[0]
 
         if built_wheel.endswith('none-any.whl'):
@@ -101,11 +95,11 @@ def build(project_dir, package_name, output_dir, test_command, test_requires, be
         delocated_wheel = glob('/tmp/delocated_wheel/*.whl')[0]
 
         # install the wheel
-        call([pip, 'install', delocated_wheel], env=env)
+        call(['pip', 'install', delocated_wheel], env=env)
 
         # test the wheel
         if test_requires:
-            call([pip, 'install'] + test_requires, env=env)
+            call(['pip', 'install'] + test_requires, env=env)
         if test_command:
             # run the tests from $HOME, with an absolute path in the command
             # (this ensures that Python runs the tests against the installed wheel
diff --git a/cibuildwheel/util.py b/cibuildwheel/util.py
index d860beeb..e15d2ddd 100644
--- a/cibuildwheel/util.py
+++ b/cibuildwheel/util.py
@@ -1,18 +1,6 @@
 from fnmatch import fnmatch
 
 
-def prepare_command(command, python, pip):
-    '''
-    Preprocesses a command by expanding variables like {python} or {pip}.
-
-    For example, used for the before_build option, where the user would
-    like to run a command like `python setup.py test`. If the command should run on
-    Python 3, the user could write `{python} setup.py test`. This command would expand
-    it out to python2 or python3 as appropriate.
-    '''
-    return command.format(python=python, pip=pip)
-
-
 class BuildSkipper(object):
     def __init__(self, skip_config):
         self.patterns = skip_config.split()
diff --git a/cibuildwheel/windows.py b/cibuildwheel/windows.py
index 3c962af9..1ea37128 100644
--- a/cibuildwheel/windows.py
+++ b/cibuildwheel/windows.py
@@ -7,7 +7,7 @@ except ImportError:
 from collections import namedtuple
 from glob import glob
 
-from .util import prepare_command, Unbuffered
+from .util import Unbuffered
 
 
 def build(project_dir, package_name, output_dir, test_command, test_requires, before_build, skip, environment):
@@ -78,8 +78,7 @@ def build(project_dir, package_name, output_dir, test_command, test_requires, be
 
         # run the before_build command
         if before_build:
-            before_build_prepared = prepare_command(before_build, python='python', pip='pip')
-            shell([before_build_prepared], env=env)
+            shell([before_build], env=env)
 
         # build the wheel
         shell(['pip', 'wheel', abs_project_dir, '-w', built_wheel_dir, '--no-deps'], env=env)