diff --git a/pipenv/utils.py b/pipenv/utils.py
index 2c815b6f..2b1d3b39 100644
--- a/pipenv/utils.py
+++ b/pipenv/utils.py
@@ -47,6 +47,12 @@ from contextlib import contextmanager
 from .pep508checker import lookup
 from .environments import PIPENV_MAX_ROUNDS, PIPENV_CACHE_DIR
 
+from prettytoml.elements.abstracttable import AbstractTable
+try:
+    from collections.abc import Mapping
+except ImportError:
+    from collections import Mapping
+
 if six.PY2:
 
     class ResourceWarning(Warning):
@@ -639,6 +645,8 @@ def is_star(val):
 
 
 def is_pinned(val):
+    if isinstance(val, Mapping) or isinstance(val, AbstractTable):
+        val = val.get('version')
     return isinstance(val, six.string_types) and val.startswith('==')
 
 
diff --git a/tests/integration/test_lock.py b/tests/integration/test_lock.py
index 29d472e5..f71e02b3 100644
--- a/tests/integration/test_lock.py
+++ b/tests/integration/test_lock.py
@@ -50,6 +50,43 @@ flask = "==0.12.2"
             assert req in d.out
 
 
+@pytest.mark.lock
+def test_lock_keep_outdated(PipenvInstance, pypi):
+
+    with PipenvInstance(pypi=pypi) as p:
+        with open(p.pipfile_path, 'w') as f:
+            contents = """
+[packages]
+requests = {version = "==2.14.0"}
+PyTest = "==3.1.0"
+            """.strip()
+            f.write(contents)
+
+        c = p.pipenv('lock')
+        assert c.return_code == 0
+        lock = p.lockfile
+        assert 'requests' in lock['default']
+        assert lock['default']['requests']['version'] == "==2.14.0"
+        assert 'pytest' in lock['default']
+        assert lock['default']['pytest']['version'] == "==3.1.0"
+
+        with open(p.pipfile_path, 'w') as f:
+            updated_contents = """
+[packages]
+requests = {version = "==2.18.4"}
+PyTest = "*"
+            """.strip()
+            f.write(updated_contents)
+
+        c = p.pipenv('lock --keep-outdated')
+        assert c.return_code == 0
+        lock = p.lockfile
+        assert 'requests' in lock['default']
+        assert lock['default']['requests']['version'] == "==2.18.4"
+        assert 'pytest' in lock['default']
+        assert lock['default']['pytest']['version'] == "==3.1.0"
+
+
 @pytest.mark.lock
 @pytest.mark.complex
 @pytest.mark.needs_internet