Don't normalize name when writing Pipfile

news/3324.bugfix.rst

@@ -0,0 +1 @@
+Don't normalize the package name user passes in.

pipenv/project.py

@@ -940,7 +940,7 @@ def add_package_to_pipfile(self, package, dev=False):
             # Skip for wildcard version
             return
         # Add the package to the group.
-        p[key][name or package.normalized_name] = converted
+        p[key][name or pep423_name(package.name)] = converted
         # Write Pipfile.
         self.write_toml(p)
 

tests/integration/test_install_basic.py

@@ -438,3 +438,11 @@ def test_install_non_exist_dep(PipenvInstance, pypi):
         c = p.pipenv("install dateutil")
         assert not c.ok
         assert "dateutil" not in p.pipfile["packages"]
+
+
+@pytest.mark.install
+def test_install_package_with_dots(PipenvInstance, pypi):
+    with PipenvInstance(pypi=pypi, chdir=True) as p:
+        c = p.pipenv("install backports.html")
+        assert c.ok
+        assert "backports.html" in p.pipfile["packages"]