diff --git a/news/4141.bugfix.rst b/news/4141.bugfix.rst
new file mode 100644
index 00000000..7a60a91d
--- /dev/null
+++ b/news/4141.bugfix.rst
@@ -0,0 +1 @@
+Fix a bug where passing --skip-lock when PIPFILE has no [SOURCE] section throws the error: "tomlkit.exceptions.NonExistentKey: 'Key "source" does not exist.'"
\ No newline at end of file
diff --git a/pipenv/project.py b/pipenv/project.py
index dd86fc89..90ff16fb 100644
--- a/pipenv/project.py
+++ b/pipenv/project.py
@@ -821,8 +821,10 @@ class Project(object):
         from .vendor.plette.lockfiles import PIPFILE_SPEC_CURRENT
         if self.lockfile_exists:
             sources = self.lockfile_content.get("_meta", {}).get("sources", [])
-        else:
+        elif "source" in self.parsed_pipfile:
             sources = [dict(source) for source in self.parsed_pipfile["source"]]
+        else:
+            sources = self.pipfile_sources
         if not isinstance(sources, list):
             sources = [sources]
         return {
diff --git a/tests/integration/test_project.py b/tests/integration/test_project.py
index dac05d34..44872b0e 100644
--- a/tests/integration/test_project.py
+++ b/tests/integration/test_project.py
@@ -230,3 +230,17 @@ def test_run_in_virtualenv(PipenvInstance):
         c = p.pipenv("clean --dry-run")
         assert c.return_code == 0
         assert "click" in c.out
+
+@pytest.mark.project
+@pytest.mark.sources
+def test_no_sources_in_pipfile(PipenvInstance):
+    with PipenvInstance(chdir=True) as p:
+        with open(p.pipfile_path, 'w') as f:
+            contents = """
+[packages]
+pytest = "*"
+            """.format(os.environ['PIPENV_TEST_INDEX']).strip()
+            f.write(contents)
+        c = p.pipenv('install --skip-lock')
+        assert c.return_code == 0
+