diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 5a8c7dd..8392eaa 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -9,4 +9,5 @@
 - Add function to assert that an object is an instance of a specific type
 - Add python project documentation generator class
 - Add python namespaces classes
-- Add type checking for the `name` attribute at the constructor of `core.python.namespaces.PythonNamespace`
\ No newline at end of file
+- Add type checking for the `name` attribute at the constructor of `core.python.namespaces.PythonNamespace`
+- Add check whether sub namespaces are not empty in `core.python.namespaces.PythonPackageNamespace.namespace`
\ No newline at end of file
diff --git a/src/jcloud_docsgen/core/python/namespaces.py b/src/jcloud_docsgen/core/python/namespaces.py
index 120f51c..5e8c5b5 100644
--- a/src/jcloud_docsgen/core/python/namespaces.py
+++ b/src/jcloud_docsgen/core/python/namespaces.py
@@ -57,6 +57,10 @@ class PythonPackageNamespace(PythonNamespace):
         if not sub_namespaces:
             raise InvalidNamespaceError('invalid namespace')
 
+        for sn in sub_namespaces:
+            if not sn:
+                raise InvalidNamespaceError('invalid namespace')
+
         # check whether the sub namespace exists
         if sub_namespaces[0] not in self.sub_namespaces:
             raise NamespaceNotFoundError('no such namespace', namespace_identifier = sub_namespaces[0])