diff --git a/src/jcloud_docsgen/core/python/_core.py b/src/jcloud_docsgen/core/python/_core.py
index 78b3f14..5e2cd6b 100644
--- a/src/jcloud_docsgen/core/python/_core.py
+++ b/src/jcloud_docsgen/core/python/_core.py
@@ -37,7 +37,11 @@ from .definitions import (
     PythonFunctionDefinition,
 )
 from .docstrings import PythonDocstring
-from .namespaces import PythonModuleNamespace, PythonPackageNamespace
+from .namespaces import (
+    PythonModuleNamespace,
+    PythonPackageNamespace,
+    validate_namespace_name,
+)
 
 __all__ = [
     'PythonDefinitionDocumentationIncludeSections',
@@ -926,9 +930,12 @@ class PythonModuleDocumentationGenerator:
         ),
         **kwargs,
     ) -> None:
-        if module_path.name.count('.') > 1:
+        if not (
+            module_path.suffix == '.py'
+            and validate_namespace_name(module_path.stem)
+        ):
             raise InvalidNamespaceError(
-                'namespace identifier cannot contain more than one dot',
+                'invalid module file name',
                 namespace_identifier=module_path.name,
             )
 
diff --git a/src/jcloud_docsgen/core/python/namespaces.py b/src/jcloud_docsgen/core/python/namespaces.py
index 706a816..4391cff 100644
--- a/src/jcloud_docsgen/core/python/namespaces.py
+++ b/src/jcloud_docsgen/core/python/namespaces.py
@@ -14,6 +14,7 @@
 
 from __future__ import annotations
 
+import keyword
 from typing import TypeAlias, Union
 
 from ...exceptions import (
@@ -24,27 +25,47 @@ from ...exceptions import (
 from ...utils import assert_that_is_instance
 
 __all__ = [
+    'validate_namespace_name',
     'PythonNamespace',
     'PythonPackageNamespace',
     'PythonModuleNamespace',
 ]
 
 
+def validate_namespace_name(name: str) -> bool:
+    """
+    Checks whether a namespace name is valid. Namespace names are valid
+    if they contain no dots and are valid Python identifiers.
+
+    :param name: The namespace name to validate.
+    :type name: str
+
+    :returns: Whether the namespace name is valid.
+    :rtype: bool
+    """
+
+    if not isinstance(name, str):
+        return False
+
+    return name.isidentifier() and not keyword.iskeyword(name)
+
+
 class PythonNamespace:
     """
     The base class for all Python namespaces such as modules or packages.
 
     :param name: The name of the namespace.
     :type name: str
+
+    :raises InvalidNamespaceError: If the namespace  name is invalid.
     """
 
     def __init__(self, name: str) -> None:
         assert_that_is_instance(name, str)
 
-        if not name.strip():
+        if not validate_namespace_name(name):
             raise InvalidNamespaceError(
-                'invalid namespace',
-                namespace_identifier=name,
+                'invalid namespace', namespace_identifier=name
             )
 
         self.name = name
@@ -70,6 +91,8 @@ class PythonPackageNamespace(PythonNamespace):
     :type name: str
     :param sub_namespaces: The sub-namespaces.
     :type sub_namespaces: list[PythonNamespace]
+
+    :raises InvalidNamespaceError: If the namespace name is invalid.
     """
 
     def __init__(
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c b/tests/unit/core/python/_core/invalid_module_names/a.b.c
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.h b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.h
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.h
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.h
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.h.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.h.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.h.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.h.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.g.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.g.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.f.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.f.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.e.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.e.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.d.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.d.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.d.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.py b/tests/unit/core/python/_core/invalid_module_names/a.b.c.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.c.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.c.py
diff --git a/tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.py b/tests/unit/core/python/_core/invalid_module_names/a.b.py
similarity index 100%
rename from tests/unit/core/python/_core/files_with_more_than_one_dot/a.b.py
rename to tests/unit/core/python/_core/invalid_module_names/a.b.py
diff --git a/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py b/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
index 33c63b7..03921c9 100644
--- a/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
+++ b/tests/unit/core/python/_core/test_PythonModuleDocumentationGenerator.py
@@ -25,176 +25,134 @@ from src.jcloud_docsgen.exceptions import InvalidNamespaceError
     [
         (
             pathlib.Path(
-                (
-                    'tests/unit/core/python/_core/fil'
-                    'es_with_more_than_one_dot/a.b.c'
-                ),
+                ('tests/unit/core/python/_core/invalid_module_names/a.b.c'),
             ),
             None,
             InvalidNamespaceError,
-            'namespace identifier cannot contain more than one dot: a.b.c',
+            'invalid module file name: a.b.c',
+        ),
+        (
+            pathlib.Path(
+                ('tests/unit/core/python/_core/invalid_module_names/a.b.c.d'),
+            ),
+            None,
+            InvalidNamespaceError,
+            'invalid module file name: a.b.c.d',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/file'
-                    's_with_more_than_one_dot/a.b.c.d'
+                    'tests/unit/core/python/_core/i'
+                    'nvalid_module_names/a.b.c.d.e'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            'namespace identifier cannot contain more than one dot: a.b.c.d',
+            'invalid module file name: a.b.c.d.e',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files'
-                    '_with_more_than_one_dot/a.b.c.d.e'
+                    'tests/unit/core/python/_core/in'
+                    'valid_module_names/a.b.c.d.e.f'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot cont'
-                'ain more than one dot: a.b.c.d.e'
-            ),
+            'invalid module file name: a.b.c.d.e.f',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_'
-                    'with_more_than_one_dot/a.b.c.d.e.f'
+                    'tests/unit/core/python/_core/inv'
+                    'alid_module_names/a.b.c.d.e.f.g'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot conta'
-                'in more than one dot: a.b.c.d.e.f'
-            ),
+            'invalid module file name: a.b.c.d.e.f.g',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_w'
-                    'ith_more_than_one_dot/a.b.c.d.e.f.g'
+                    'tests/unit/core/python/_core/inva'
+                    'lid_module_names/a.b.c.d.e.f.g.h'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contai'
-                'n more than one dot: a.b.c.d.e.f.g'
-            ),
+            'invalid module file name: a.b.c.d.e.f.g.h',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_wi'
-                    'th_more_than_one_dot/a.b.c.d.e.f.g.h'
+                    'tests/unit/core/python/_core/inval'
+                    'id_module_names/a.b.c.d.e.f.g.h.py'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contain'
-                ' more than one dot: a.b.c.d.e.f.g.h'
-            ),
+            'invalid module file name: a.b.c.d.e.f.g.h.py',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_wit'
-                    'h_more_than_one_dot/a.b.c.d.e.f.g.h.py'
+                    'tests/unit/core/python/_core/inva'
+                    'lid_module_names/a.b.c.d.e.f.g.py'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contain m'
-                'ore than one dot: a.b.c.d.e.f.g.h.py'
-            ),
+            'invalid module file name: a.b.c.d.e.f.g.py',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_wi'
-                    'th_more_than_one_dot/a.b.c.d.e.f.g.py'
+                    'tests/unit/core/python/_core/in'
+                    'lid_module_names/a.b.c.d.e.f.py'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contain '
-                'more than one dot: a.b.c.d.e.f.g.py'
-            ),
+            'invalid module file name: a.b.c.d.e.f.py',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_w'
-                    'ith_more_than_one_dot/a.b.c.d.e.f.py'
+                    'tests/unit/core/python/_core/in'
+                    'valid_module_names/a.b.c.d.e.py'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contain'
-                ' more than one dot: a.b.c.d.e.f.py'
-            ),
+            'invalid module file name: a.b.c.d.e.py',
         ),
         (
             pathlib.Path(
                 (
-                    'tests/unit/core/python/_core/files_'
-                    'with_more_than_one_dot/a.b.c.d.e.py'
+                    'tests/unit/core/python/_core/i'
+                    'nvalid_module_names/a.b.c.d.py'
                 ),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot contai'
-                'n more than one dot: a.b.c.d.e.py'
-            ),
+            'invalid module file name: a.b.c.d.py',
         ),
         (
             pathlib.Path(
-                (
-                    'tests/unit/core/python/_core/files'
-                    '_with_more_than_one_dot/a.b.c.d.py'
-                ),
+                ('tests/unit/core/python/_core/invalid_module_names/a.b.c.py'),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot conta'
-                'in more than one dot: a.b.c.d.py'
-            ),
+            'invalid module file name: a.b.c.py',
         ),
         (
             pathlib.Path(
-                (
-                    'tests/unit/core/python/_core/file'
-                    's_with_more_than_one_dot/a.b.c.py'
-                ),
+                ('tests/unit/core/python/_core/invalid_module_names/a.b.py'),
             ),
             None,
             InvalidNamespaceError,
-            (
-                'namespace identifier cannot cont'
-                'ain more than one dot: a.b.c.py'
-            ),
-        ),
-        (
-            pathlib.Path(
-                (
-                    'tests/unit/core/python/_core/fil'
-                    'es_with_more_than_one_dot/a.b.py'
-                ),
-            ),
-            None,
-            InvalidNamespaceError,
-            'namespace identifier cannot contain more than one dot: a.b.py',
+            'invalid module file name: a.b.py',
         ),
         (
             pathlib.Path(
@@ -205,7 +163,7 @@ from src.jcloud_docsgen.exceptions import InvalidNamespaceError
             ),
             None,
             InvalidNamespaceError,
-            'namespace identifier cannot contain more than one dot: a.b.py',
+            'invalid module file name: a.b.py',
         ),
     ],
 )
diff --git a/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py b/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
index 53d7e0e..3f86f7f 100644
--- a/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonModuleNamespace.py
@@ -28,7 +28,6 @@ class StrSubclass(str): ...
     'namespace,expected_name',
     [
         (PythonModuleNamespace('a'), 'a'),
-        (PythonModuleNamespace('1'), '1'),
         (PythonModuleNamespace(StrSubclass('a')), StrSubclass('a')),
     ],
 )
@@ -41,11 +40,7 @@ def test_PythonModuleNamespace_name_attribute(namespace, expected_name):
     [
         (PythonModuleNamespace('a'), PythonModuleNamespace('a'), True),
         (PythonModuleNamespace('b'), PythonModuleNamespace('b'), True),
-        (PythonModuleNamespace('1'), PythonModuleNamespace('1'), True),
-        (PythonModuleNamespace('42'), PythonModuleNamespace('42'), True),
         (PythonModuleNamespace('a'), PythonModuleNamespace('b'), False),
-        (PythonModuleNamespace('0'), PythonModuleNamespace('-0'), False),
-        (PythonModuleNamespace('1'), PythonModuleNamespace('a'), False),
         (PythonModuleNamespace('a'), 'a', False),
         (PythonModuleNamespace('a'), 'b', False),
         (PythonModuleNamespace('a'), PythonPackageNamespace('a', []), False),
@@ -61,7 +56,6 @@ def test_PythonModuleNamespace___eq__(namespace1, namespace2, expected):
     'namespace,expected',
     [
         (PythonModuleNamespace('a'), "PythonModuleNamespace('a')"),
-        (PythonModuleNamespace('1'), "PythonModuleNamespace('1')"),
         (
             PythonModuleNamespace(StrSubclass('a')),
             "PythonModuleNamespace('a')",
diff --git a/tests/unit/core/python/namespaces/test_PythonNamespace.py b/tests/unit/core/python/namespaces/test_PythonNamespace.py
index e4ee640..ba56d89 100644
--- a/tests/unit/core/python/namespaces/test_PythonNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonNamespace.py
@@ -24,7 +24,6 @@ class StrSubclass(str): ...
     'namespace,expected_name',
     [
         (PythonNamespace('a'), 'a'),
-        (PythonNamespace('1'), '1'),
         (PythonNamespace(StrSubclass('a')), StrSubclass('a')),
     ],
 )
@@ -36,7 +35,6 @@ def test_PythonNamespace_name_attribute(namespace, expected_name):
     'namespace,expected',
     [
         (PythonNamespace('a'), "PythonNamespace('a')"),
-        (PythonNamespace('1'), "PythonNamespace('1')"),
         (PythonNamespace(StrSubclass('a')), "PythonNamespace('a')"),
     ],
 )
diff --git a/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py b/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
index 1087cf0..30ca226 100644
--- a/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
+++ b/tests/unit/core/python/namespaces/test_PythonPackageNamespace.py
@@ -38,13 +38,6 @@ class StrSubclass(str): ...
             ),
             'a',
         ),
-        (
-            PythonPackageNamespace(
-                '1',
-                [],
-            ),
-            '1',
-        ),
         (
             PythonPackageNamespace(
                 StrSubclass('a'),
@@ -291,10 +284,6 @@ def test_PythonPackageNamespace___eq__(namespace1, namespace2, expected):
             PythonPackageNamespace('a', []),
             "PythonPackageNamespace('a', [])",
         ),
-        (
-            PythonPackageNamespace('1', []),
-            "PythonPackageNamespace('1', [])",
-        ),
         (
             PythonPackageNamespace(StrSubclass('a'), []),
             "PythonPackageNamespace('a', [])",