diff --git a/httpie/input.py b/httpie/input.py
index 1efa4f41..c05fa9b8 100644
--- a/httpie/input.py
+++ b/httpie/input.py
@@ -8,6 +8,7 @@ import json
 import mimetypes
 import getpass
 from io import BytesIO
+from collections import namedtuple
 #noinspection PyCompatibility
 from argparse import ArgumentParser, ArgumentTypeError, ArgumentError
 
@@ -560,6 +561,10 @@ class ParamDict(OrderedDict):
             self[key].append(value)
 
 
+RequestItems = namedtuple('RequestItems',
+                          ['headers', 'data', 'files', 'params'])
+
+
 def parse_items(items, data=None, headers=None, files=None, params=None):
     """Parse `KeyValue` `items` into `data`, `headers`, `files`,
     and `params`.
@@ -617,7 +622,7 @@ def parse_items(items, data=None, headers=None, files=None, params=None):
 
         target[item.key] = value
 
-    return headers, data, files, params
+    return RequestItems(headers, data, files, params)
 
 
 def readable_file_arg(filename):
diff --git a/setup.py b/setup.py
index 3e2917c4..4e93a6d5 100644
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,5 @@
+# This is purely the result of trial and error.
+
 import sys
 import codecs
 
@@ -26,7 +28,7 @@ class PyTest(TestCommand):
 
 tests_require = [
     # Pytest needs to come last.
-    # <bitbucket.org/pypa/setuptools/issue/196/tests_require-pytest-pytest-cov-breaks>
+    # https://bitbucket.org/pypa/setuptools/issue/196/
     'pytest-httpbin',
     'pytest',
 ]
@@ -36,15 +38,30 @@ install_requires = [
     'requests>=2.3.0',
     'Pygments>=1.5'
 ]
-try:
-    #noinspection PyUnresolvedReferences
-    import argparse
-except ImportError:
-    install_requires.append('argparse>=1.2.1')
 
-if 'win32' in str(sys.platform).lower():
-    # Terminal colors for Windows
-    install_requires.append('colorama>=0.2.4')
+### Conditional dependencies:
+
+# sdist
+if not 'bdist_wheel' in sys.argv:
+    try:
+        #noinspection PyUnresolvedReferences
+        import argparse
+    except ImportError:
+        install_requires.append('argparse>=1.2.1')
+
+    if 'win32' in str(sys.platform).lower():
+        # Terminal colors for Windows
+        install_requires.append('colorama>=0.2.4')
+
+
+# bdist_wheel
+extras_require = {
+    # http://wheel.readthedocs.org/en/latest/#defining-conditional-dependencies
+    ':python_version == "2.6"'
+    ' or python_version == "3.0"'
+    ' or python_version == "3.1" ': ['argparse>=1.2.1'],
+    ':sys_platform == "win32"': ['colorama>=0.2.4'],
+}
 
 
 def long_description():
@@ -67,6 +84,7 @@ setup(
             'http = httpie.__main__:main',
         ],
     },
+    extras_require=extras_require,
     install_requires=install_requires,
     tests_require=tests_require,
     cmdclass={'test': PyTest},
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 103d9543..f8009153 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -27,32 +27,32 @@ class TestItemParsing:
                           self.key_value_type, item)
 
     def test_escape(self):
-        headers, data, files, params = input.parse_items([
+        items = input.parse_items([
             # headers
-            self.key_value_type('foo\\:bar:baz'),
-            self.key_value_type('jack\\@jill:hill'),
+            self.key_value_type(r'foo\:bar:baz'),
+            self.key_value_type(r'jack\@jill:hill'),
             # data
-            self.key_value_type('baz\\=bar=foo'),
+            self.key_value_type(r'baz\=bar=foo'),
             # files
-            self.key_value_type('bar\\@baz@%s' % FILE_PATH_ARG)
+            self.key_value_type(r'bar\@baz@%s' % FILE_PATH_ARG)
         ])
         # `requests.structures.CaseInsensitiveDict` => `dict`
-        headers = dict(headers._store.values())
+        headers = dict(items.headers._store.values())
         assert headers == {
             'foo:bar': 'baz',
             'jack@jill': 'hill',
         }
-        assert data == {'baz=bar': 'foo'}
-        assert 'bar@baz' in files
+        assert items.data == {'baz=bar': 'foo'}
+        assert 'bar@baz' in items.files
 
     def test_escape_longsep(self):
-        headers, data, files, params = input.parse_items([
-            self.key_value_type('bob\\:==foo'),
+        items = input.parse_items([
+            self.key_value_type(r'bob\:==foo'),
         ])
-        assert params == {'bob:': 'foo'}
+        assert items.params == {'bob:': 'foo'}
 
     def test_valid_items(self):
-        headers, data, files, params = input.parse_items([
+        items = input.parse_items([
             self.key_value_type('string=value'),
             self.key_value_type('header:value'),
             self.key_value_type('list:=["a", 1, {}, false]'),
@@ -68,14 +68,14 @@ class TestItemParsing:
 
         # Parsed headers
         # `requests.structures.CaseInsensitiveDict` => `dict`
-        headers = dict(headers._store.values())
+        headers = dict(items.headers._store.values())
         assert headers == {'header': 'value', 'eh': ''}
 
         # Parsed data
-        raw_json_embed = data.pop('raw-json-embed')
+        raw_json_embed = items.data.pop('raw-json-embed')
         assert raw_json_embed == json.loads(JSON_FILE_CONTENT)
-        data['string-embed'] = data['string-embed'].strip()
-        assert dict(data) == {
+        items.data['string-embed'] = items.data['string-embed'].strip()
+        assert dict(items.data) == {
             "ed": "",
             "string": "value",
             "bool": True,
@@ -85,11 +85,12 @@ class TestItemParsing:
         }
 
         # Parsed query string parameters
-        assert params == {'query': 'value'}
+        assert items.params == {'query': 'value'}
 
         # Parsed file fields
-        assert 'file' in files
-        assert files['file'][1].read().strip().decode('utf8') == FILE_CONTENT
+        assert 'file' in items.files
+        assert (items.files['file'][1].read().strip().decode('utf8')
+                == FILE_CONTENT)
 
 
 class TestQuerystring: