diff --git a/.pkglts/pkg_cfg.json b/.pkglts/pkg_cfg.json
index d82ac8f8..4e20fdcd 100644
--- a/.pkglts/pkg_cfg.json
+++ b/.pkglts/pkg_cfg.json
@@ -125,6 +125,6 @@
   "version": {
     "major": 4,
     "minor": 2,
-    "post": 0
+    "post": 1
   }
 }
\ No newline at end of file
diff --git a/.pkglts/pkg_hash.json b/.pkglts/pkg_hash.json
index 11e22356..1465d1fd 100644
--- a/.pkglts/pkg_hash.json
+++ b/.pkglts/pkg_hash.json
@@ -43,7 +43,7 @@
   },
   "conda/meta.yaml": {
     "conda.about": "6/RoaDh45Wwcc0uAhKGnUH46mczqPBQq/PV0cSCbe+fhiDQPOooOK8u24GzswyAcXIEHoASc/XIe+WS/2zBl5A==",
-    "conda.package": "WmgEFfGMZPgK5viuWYnIjyOW6d3o30Lfnb4tOu1F1G+PQ2NA2mEusQrcMS12h3+/TwkXIo2EedHbzlQAZ6Yf3Q==",
+    "conda.package": "zVISR+6Wjkm6gSFk/wzS4doAf9D6G8ccDddpv6qrLnEwlkpj1kqxsxV5+boomAnxQH3lZVbNhRVwn4RWP85BuA==",
     "conda.req_build": "STnNeGQNdKNtp0ZDkfZ9RqPnmFYfv1p31EavfN1V6ogusq9KBD+sFzDaFK8r9xu+pqXupiyeBc1T/MIqJWYXJg==",
     "conda.req_run": "IFJIX6NLBagkPhLDSOvcHHj/XiggVhFfvIRKy/vGjLnBm8TsaqXFdb8wX1l/l4GJaGjfNUA3+MOT+tGumt8uPw==",
     "conda.src": "Lzbp176AVU0YantZQxB4LsR2jbxpZ/OlkvY2V4aWAEuzKEarh872uc1eRvsIYf/FsbxvcmUI84AezWlA72nI6A=="
@@ -63,7 +63,7 @@
   "doc/_static/nonempty.txt": {},
   "doc/authors.rst": {},
   "doc/conf.py": {
-    "sphinx": "dgV/5SXYGOM1vpfUUrHkBWYqzmdA1rZD21JtTfT/uEsh00gcGuSinPAGoWuq1kz9gwPznF1ySIQKAO1h58CT7Q=="
+    "sphinx": "kebxgaBoeF8bxLKpy1H45nl8eNH5F3zBGK3H1x9xG3PseoM75wTrPiNPkQl5RKkbLZG9TdwN7XSBfvYuk4JerA=="
   },
   "doc/contributing.rst": {},
   "doc/history.rst": {},
@@ -94,7 +94,7 @@
   },
   "setup.py": {
     "pysetup.call": "t30iIuCMd/sWxStR2XNYb8bCBgwanhKt8YYn2VKACyAqL5cKFRUWpVRIpAR+uxXUZ9PYYy2csMmECcONnRZE8w==",
-    "pysetup.kwds": "19LGQMJ/3o5j6tV+eOEEujqmfK8PCWNJAU2oDUDkKn3O3o8PEWf97CTSMTZ4xZvYnOzezI7CHOmPUgluTLuWKQ=="
+    "pysetup.kwds": "sdru1Qz1bjccdxKUF1Jft8aQLkeGlGBIsp2i0XGne31vQZnZbW4bW4uQMRdtRYjJFqp7KzQGIvAUKB/TrnuHQg=="
   },
   "src/pkglts/__init__.py": {
     "base": "+GVGxVjJGifAp8dAR9V2W3aVPe7/D53bN7r0O5VxO9OUqG4vnGTZvnORu1objjjIwm86DgemQd7ax/IJpRa8Wg=="
@@ -103,7 +103,7 @@
     "data": "wwgLuV/OqHWjWbssvDHa4LNg+7C+tuNiKHOxkO+9UAl9opI/HfPyJAq2fPhUeTmVvb/E6MkqDJIli9m8n5/V0Q=="
   },
   "src/pkglts/version.py": {
-    "version": "MW1Gvc90300wkLZ3GZRFboia8R27YDKyHr+PJU5kNB9rivmkTPR8D3knOCko4Z96dsq2IoYmCAftuXwMTL/9KQ=="
+    "version": "lODR9Wcl/9MYQIrArXjlsYwrOh8o0JuC2ycMdHiMb9Xy58TPVKu7N5qsEcNwyJN2nXnD1+lO5dzkmfhBpIcNNQ=="
   },
   "src/pkglts_data/__init__.py": {},
   "test/__init__.py": {},
diff --git a/.pkglts/pkg_version.json b/.pkglts/pkg_version.json
index de67a961..5d6f1922 100644
--- a/.pkglts/pkg_version.json
+++ b/.pkglts/pkg_version.json
@@ -1,24 +1,24 @@
 {
-  "appveyor": "4.1.1",
-  "base": "4.1.1",
-  "conda": "4.1.1",
-  "coverage": "4.1.1",
-  "coveralls": "4.1.1",
-  "data": "4.1.1",
-  "doc": "4.1.1",
-  "flake8": "4.1.1",
-  "git": "4.1.1",
-  "github": "4.1.1",
-  "landscape": "4.1.1",
-  "license": "4.1.1",
-  "notebook": "4.1.1",
-  "pypi": "4.1.1",
-  "pysetup": "4.1.1",
-  "readthedocs": "4.1.1",
-  "requires": "4.1.1",
-  "sphinx": "4.1.1",
-  "test": "4.1.1",
-  "tox": "4.1.1",
-  "travis": "4.1.1",
-  "version": "4.1.1"
+  "appveyor": "4.2.0",
+  "base": "4.2.0",
+  "conda": "4.2.0",
+  "coverage": "4.2.0",
+  "coveralls": "4.2.0",
+  "data": "4.2.0",
+  "doc": "4.2.0",
+  "flake8": "4.2.0",
+  "git": "4.2.0",
+  "github": "4.2.0",
+  "landscape": "4.2.0",
+  "license": "4.2.0",
+  "notebook": "4.2.0",
+  "pypi": "4.2.0",
+  "pysetup": "4.2.0",
+  "readthedocs": "4.2.0",
+  "requires": "4.2.0",
+  "sphinx": "4.2.0",
+  "test": "4.2.0",
+  "tox": "4.2.0",
+  "travis": "4.2.0",
+  "version": "4.2.0"
 }
\ No newline at end of file
diff --git a/conda/meta.yaml b/conda/meta.yaml
index c7d3a72c..1c3cc203 100644
--- a/conda/meta.yaml
+++ b/conda/meta.yaml
@@ -1,7 +1,7 @@
 # {# pkglts, conda.package
 package:
   name: pkglts
-  version: "4.2.0"
+  version: "4.2.1"
 # #}
 
 # {# pkglts, conda.src
diff --git a/doc/conf.py b/doc/conf.py
index c7fe1f62..a7384f1d 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -95,9 +95,9 @@
 #
 
 # The short X.Y version.
-version = "4.2.0"
+version = "4.2.1"
 # The full version, including alpha/beta/rc tags.
-release = "4.2.0"
+release = "4.2.1"
 
 
 # The language for content autogenerated by Sphinx. Refer to documentation
diff --git a/setup.py b/setup.py
index a148e6ea..57ef6852 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@
 
 setup_kwds = dict(
     name='pkglts',
-    version="4.2.0",
+    version="4.2.1",
     description=short_descr,
     long_description=readme + '\n\n' + history,
     author="revesansparole",
diff --git a/src/pkglts/dependency.py b/src/pkglts/dependency.py
index 8e022956..4b757b73 100644
--- a/src/pkglts/dependency.py
+++ b/src/pkglts/dependency.py
@@ -53,9 +53,22 @@ def _pip_fmt_name(self):
             version = ""
         else:
             version = self.version
-            if version[:2] not in ('==', '>=', '<=', "~="):
-                if len(version.split(".")) < 3:
-                    version = ">=" + version
+            if version[:2] in ('==', '>=', '<=', "~="):
+                # full formatter already do nothing
+                pass
+            elif version[0] == '=':
+                # transform into '=='
+                version = "=" + version
+            else:
+                # no formatter at all use heuristic to include one
+                if len(version.split(".")) == 1:
+                    major = int(version)
+                    next_version = "{:d}".format(major + 1)
+                    version = ">=" + version + ", <" + next_version
+                elif len(version.split(".")) == 2:
+                    major, minor = (int(v) for v in version.split("."))
+                    next_version = "{:d}.{:d}".format(major, minor + 1)
+                    version = ">=" + version + ", <" + next_version
                 else:
                     version = "==" + version
         return "{}{}".format(self.name, version)
diff --git a/src/pkglts/option/pysetup/option.py b/src/pkglts/option/pysetup/option.py
index a305d1b0..d867ab15 100644
--- a/src/pkglts/option/pysetup/option.py
+++ b/src/pkglts/option/pysetup/option.py
@@ -154,7 +154,7 @@ def fmt_conda_reqs(reqs, intents):
     for channel in set(r.channel for r in reqs) - {None}:
         cmd += " -c %s" % channel
 
-    for name in sorted(r.name for r in reqs):
+    for name in sorted(r.conda_full_name() for r in reqs):
         cmd += " %s" % name
 
     return cmd
@@ -176,7 +176,7 @@ def fmt_pip_reqs(reqs, intents):
 
     cmd = "pip install"
 
-    for name in sorted(r.name for r in reqs):
+    for name in sorted(r.pip_full_name() for r in reqs):
         cmd += " %s" % name
 
     return cmd
diff --git a/src/pkglts/version.py b/src/pkglts/version.py
index 942e8228..877b7f71 100644
--- a/src/pkglts/version.py
+++ b/src/pkglts/version.py
@@ -10,7 +10,7 @@
 MINOR = 2
 """(int) Version minor component."""
 
-POST = 0
+POST = 1
 """(int) Version post or bugfix component."""
 
 __version__ = ".".join([str(s) for s in (MAJOR, MINOR, POST)])
diff --git a/test/test_dependency.py b/test/test_dependency.py
index 1ff7fade..67b58e89 100644
--- a/test/test_dependency.py
+++ b/test/test_dependency.py
@@ -49,9 +49,9 @@ def test_dependency_writes_correct_pip_requirements():
     # version partially specified without comparison indicator
     dep = Dependency("toto", pkg_mng="pip", version="2.18")
     txt = dep.fmt_pip_requirement()
-    assert txt == "toto>=2.18"
+    assert txt == "toto>=2.18, <2.19"
     txt = dep.fmt_pip_requirement(extended=True)
-    assert txt == "toto>=2.18  # pip install toto>=2.18"
+    assert txt == "toto>=2.18, <2.19  # pip install toto>=2.18, <2.19"
 
     # version specified with comparison indicator
     dep = Dependency("toto", pkg_mng="pip", version="==2.18")
@@ -77,9 +77,9 @@ def test_dependency_writes_correct_pip_requirements():
     # version partially specified without comparison indicator conda manager
     dep = Dependency("toto", pkg_mng="conda", version="2.18")
     txt = dep.fmt_pip_requirement()
-    assert txt == "toto>=2.18"
+    assert txt == "toto>=2.18, <2.19"
     txt = dep.fmt_pip_requirement(extended=True)
-    assert txt == "toto>=2.18  # conda install toto=2.18"
+    assert txt == "toto>=2.18, <2.19  # conda install toto=2.18"
 
 
 def test_dependency_writes_correct_conda_requirements():