diff --git a/.travis.yml b/.travis.yml
index b9c0967f..e10d2400 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,6 +8,7 @@ env:
   global:
     - PYPI_VENDOR_DIR='./tests/pypi/'
     - GIT_ASK_YESNO='false'
+    - PYTHONIOENCODING='utf-8'
   matrix:
     - TEST_SUITE='not install'
     - TEST_SUITE='install'
diff --git a/pipenv/core.py b/pipenv/core.py
index ddaf5efc..05530bc3 100644
--- a/pipenv/core.py
+++ b/pipenv/core.py
@@ -1136,11 +1136,12 @@ def do_lock(
             for package_specified in section:
                 norm_name = pep423_name(package_specified)
                 if not is_pinned(section[package_specified]):
-                    lockfile[section_name][norm_name] = cached_lockfile[
-                        section_name
-                    ][
-                        norm_name
-                    ]
+                    if norm_name in cached_lockfile[section_name]:
+                        lockfile[section_name][norm_name] = cached_lockfile[
+                            section_name
+                        ][
+                            norm_name
+                        ]
     # Overwrite any develop packages with default packages.
     for default_package in lockfile['default']:
         if default_package in lockfile['develop']:
diff --git a/pipenv/project.py b/pipenv/project.py
index 4d5879c9..0127261d 100644
--- a/pipenv/project.py
+++ b/pipenv/project.py
@@ -44,6 +44,7 @@ from .environments import (
     PIPENV_VIRTUALENV,
     PIPENV_TEST_INDEX,
     PIPENV_PYTHON,
+    PIPENV_DEFAULT_PYTHON_VERSION,
 )
 
 
@@ -578,12 +579,17 @@ class Project(object):
             u'dev-packages': {},
         }
         # Default requires.
-        required_python = python or self.which(
-            'python', self.virtualenv_location
-        )
-        data[u'requires'] = {
-            'python_version': python_version(required_python)[: len('2.7')]
-        }
+        required_python = python
+        if not python:
+            if self.virtualenv_location:
+                required_python = self.which('python', self.virtualenv_location)
+            else:
+                required_python = self.which('python')
+        version = python_version(required_python) or PIPENV_DEFAULT_PYTHON_VERSION
+        if version and len(version) >= 3:
+            data[u'requires'] = {
+                'python_version': version[: len('2.7')]
+            }
         self.write_toml(data, 'Pipfile')
 
     def write_toml(self, data, path=None):
diff --git a/pipenv/utils.py b/pipenv/utils.py
index 832105fa..4a4ce008 100644
--- a/pipenv/utils.py
+++ b/pipenv/utils.py
@@ -220,8 +220,13 @@ def python_version(path_to_python):
         c = delegator.run([path_to_python, '--version'], block=False)
     except Exception:
         return None
+    c.block()
     version = parse_python_version(c.out.strip() or c.err.strip())
-    return u'{major}.{minor}.{micro}'.format(**version)
+    try:
+        version = u'{major}.{minor}.{micro}'.format(**version)
+    except TypeError:
+        return None
+    return version
 
 
 def escape_grouped_arguments(s):
diff --git a/tests/unit/test_help.py b/tests/unit/test_help.py
new file mode 100644
index 00000000..2432e969
--- /dev/null
+++ b/tests/unit/test_help.py
@@ -0,0 +1,11 @@
+import os
+import subprocess
+import sys
+
+
+def test_help():
+    output = subprocess.check_output(
+        [sys.executable, '-m', 'pipenv.help'],
+        stderr=subprocess.STDOUT, env=os.environ.copy(),
+    )
+    assert output