diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 8f32c0824..8eac46c94 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -94,6 +94,7 @@ Stephen Finucane
 Sviatoslav Sydorenko
 Thomas Grainger
 Tim Laurence
+Tyagraj Desigar
 Ville Skyttä
 Xander Johnson
 anatoly techtonik
diff --git a/docs/changelog/1636.bugfix.rst b/docs/changelog/1636.bugfix.rst
new file mode 100644
index 000000000..b9a994f9d
--- /dev/null
+++ b/docs/changelog/1636.bugfix.rst
@@ -0,0 +1 @@
+Allow hyphens and empty factors in generative section name. - by :user:`tyagdit`
diff --git a/src/tox/config/__init__.py b/src/tox/config/__init__.py
index c21222c04..891aa59af 100644
--- a/src/tox/config/__init__.py
+++ b/src/tox/config/__init__.py
@@ -1420,7 +1420,7 @@ def expand_section_names(config):
         The parser will see it as two different sections: [testenv:py36-cov], [testenv:py37-cov]
 
         """
-        factor_re = re.compile(r"\{\s*([\w\s,]+)\s*\}")
+        factor_re = re.compile(r"\{\s*([\w\s,-]+)\s*\}")
         split_re = re.compile(r"\s*,\s*")
         to_remove = set()
         for section in list(config.sections):
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index 14847c7a6..206fdc1c2 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -865,10 +865,11 @@ def test_getbool(self, newconfig):
     def test_expand_section_name(self, newconfig):
         config = newconfig(
             """
-            [testenv:custom-{one,two,three}-{four,five}-six]
+            [testenv:custom{,-one,-two,-three}-{four,five}-six]
         """,
         )
         assert "testenv:custom-one-five-six" in config._cfg.sections
+        assert "testenv:custom-four-six" in config._cfg.sections
         assert "testenv:custom-{one,two,three}-{four,five}-six" not in config._cfg.sections