diff --git a/python-rpm-generators.spec b/python-rpm-generators.spec
index 7550178..24994bf 100644
--- a/python-rpm-generators.spec
+++ b/python-rpm-generators.spec
@@ -1,7 +1,7 @@
 Name:           python-rpm-generators
 Summary:        Dependency generators for Python RPMs
 Version:        12
-Release:        3%{?dist}
+Release:        4%{?dist}
 
 # Originally all those files were part of RPM, so license is kept here
 License:        GPLv2+
@@ -47,6 +47,10 @@ install -Dpm0755 -t %{buildroot}%{_rpmconfigdir} *.py
 %{_rpmconfigdir}/pythonbundles.py
 
 %changelog
+* Thu Mar 11 2021 Tomas Orsava <torsava@redhat.com> - 12-4
+- scripts/pythondistdeps: Treat extras names case-insensitively and always
+  output them in lower case (#1936875)
+
 * Mon Feb 22 2021 Tomas Orsava <torsava@redhat.com> - 12-3
 - scripts/pythondistdeps: Fix for Python 3.10
 
diff --git a/pythondistdeps.py b/pythondistdeps.py
index b097228..f38f726 100755
--- a/pythondistdeps.py
+++ b/pythondistdeps.py
@@ -77,7 +77,7 @@ class Distribution(PathDistribution):
         self.legacy_normalized_name = legacy_normalize_name(self.name)
         self.requirements = [Requirement(r) for r in self.requires or []]
         self.extras = [
-            v for k, v in self.metadata.items() if k == 'Provides-Extra']
+            v.lower() for k, v in self.metadata.items() if k == 'Provides-Extra']
         self.py_version = self._parse_py_version(path)
 
     # `name` is defined as a property exactly like this in Python 3.10 in the
@@ -316,7 +316,7 @@ if __name__ == "__main__":
         # and pluses in the middle can be easily replaced with dashes.
         # Python extras names don't contain pluses according to PEP 508.
         package_name_parts = args.package_name.rpartition('+')
-        extras_subpackage = package_name_parts[2] or None
+        extras_subpackage = package_name_parts[2].lower() or None
 
     for f in (args.files or stdin.readlines()):
         f = f.strip()
@@ -456,7 +456,7 @@ if __name__ == "__main__":
                     if args.require_extras_subpackages and dep.extras:
                         # A dependency can have more than one extras,
                         # i.e. foo[bar,baz], so let's go through all of them
-                        extras_suffixes += [f"[{e}]" for e in dep.extras]
+                        extras_suffixes += [f"[{e.lower()}]" for e in dep.extras]
 
                     for extras_suffix in extras_suffixes:
                         if normalized_names_require_pep503:
diff --git a/tests/data/scripts_pythondistdeps/pyreq2rpm.tests-2020.04.07.024dab0-py3.9.egg-info/requires.txt b/tests/data/scripts_pythondistdeps/pyreq2rpm.tests-2020.04.07.024dab0-py3.9.egg-info/requires.txt
index 1436266..338afcc 100644
--- a/tests/data/scripts_pythondistdeps/pyreq2rpm.tests-2020.04.07.024dab0-py3.9.egg-info/requires.txt
+++ b/tests/data/scripts_pythondistdeps/pyreq2rpm.tests-2020.04.07.024dab0-py3.9.egg-info/requires.txt
@@ -100,3 +100,5 @@ hugo5===11.1.0.post3
 
 test___multiple__underscores==1
 test_underscores==1
+
+dnspython[DNSSEC]
diff --git a/tests/data/scripts_pythondistdeps/test-data.yaml b/tests/data/scripts_pythondistdeps/test-data.yaml
index 6dc4612..35c72a8 100644
--- a/tests/data/scripts_pythondistdeps/test-data.yaml
+++ b/tests/data/scripts_pythondistdeps/test-data.yaml
@@ -1193,13 +1193,15 @@
                 python3.9dist(coverage)
                 python3.9dist(nose)
                 python3.9dist(zope-testing)
---requires:
-    --provides:
+--requires --normalized-names-format pep503 --require-extras-subpackages:
+    --provides --normalized-names-format pep503:
         pyreq2rpm.tests-2020.04.07.024dab0-py3.9.egg-info:
-            provides: python3.9dist(pyreq2rpm.tests) = 2020.04.07.024dab0
+            provides: python3.9dist(pyreq2rpm-tests) = 2020.04.07.024dab0
             requires: |-
                 python(abi) = 3.9
                 ((python3.9dist(babel) < 2 or python3.9dist(babel) > 2) with python3.9dist(babel) >= 1.3)
+                python3.9dist(dnspython)
+                python3.9dist(dnspython[dnssec])
                 python3.9dist(fedora-python-nb2plots) = 0
                 (python3.9dist(foobar0) >= 2.4.8 with python3.9dist(foobar0) < 2.5)
                 (python3.9dist(foobar1) >= 2.4.8 with python3.9dist(foobar1) < 2.4.9)